Intergeneric hybrids

The other day someone linked to my post on strawberry x raspberry hybrids on Reddit and my blog post got a lot of views.  While this was really nice, I made the mistake of reading some of the comments in Reddit.  My opinion of humanity dropped somewhat when I noticed that many of the people arguing had little to no understanding of what they were saying.  Their claims were based on aggression and making up a guess on the spot, rather than any form of evidence or research.

One person claimed that intergeneric hybrids (hybrids between two different genera) cannot exist.  This person likened the possibility of a strawberry raspberry hybrid to crossing a human with a goat.  Initially I was tempted to make nasty comments about this person's lack of basic knowledge.

Then I thought about it some more and decided rather than chastise them for their ignorance and belittle them for making claims that they clearly have never researched, maybe this could be used as an educational activity.

Bumpy irregular strawberry x raspberry hybrid

Intergeneric hybrids do occur in nature.  They have been seen in plants as well as animals.

Some closely related genera are possible to hybridise, while others will never hybridise.  The ones that are possible are always closely related genera.  Strawberry (Fragaria) and raspberry (Rubus) are relatively closely related.  Human and goat are not.  Even with this knowledge trying to compare the possible cross between Rubus and Fragaria to a goat/human hybrid is completely absurd.

Intergeneric hybrids occur in animals as well as plants.  Intergeneric hybrids can be found among mammals (they are strangely common in cetaceans), birds, and reptiles as can be seen in the examples below:

Mammals: Tursiops Delphinus hybrid: https://www.nrcresearchpress.com/doi/abs/10.1139/z03-150#.XVeMDEdS_IU

Birds: Cairina Anas hybrid: https://www.cambridge.org/core/journals/proceedings-of-the-royal-society-of-edinburgh/article/xivgenetical-and-cytological-studies-of-the-intergeneric-hybrid-of-cairina-moschata-and-anas-platyrhyncha-platyrhyncha/F7FE7498CE0DA4A1641EA75E13882A3F

Reptiles:  Pituophis Pantherophis hybrid: https://bioone.org/journals/Journal-of-Herpetology/volume-46/issue-2/10-260/Two-Naturally-Occurring-Intergeneric-Hybrid-Snakes-Pituophis-catenifer-sayi-/10.1670/10-260.short

Plants and animals are biologically very different.  Many things that are common in plants are extremely rare or impossible in animals.

Proving the existence of intergeneric hybrids in animals quickly rules out the human cross goat argument, but does not do anything to back up the possibility of a strawberry x raspberry hybrid, so let's move onto plants.

Leaf edges curl - I am unsure if the cause is genetic or environmental

Intergeneric hybrids among plants:
Most people with a basic understanding of agriculture can tell you that triticale is a wheat rye hybrid.  It is common and grown on commercial scale.  Australia produces around 800,000 tonnes of triticale grain per year.  This alone proves that intergeneric hybrids among plants are possible .

Fifteen seconds on a search engine returns many thousands of intergeneric hybrids among plants, below are a few examples:

Triticum Secale hybrid: https://en.wikipedia.org/wiki/Triticale

Citrus Citropsis hybrid: http://era.daf.qld.gov.au/id/eprint/4475/

Citrus Fortunella hybrid: https://pdfs.semanticscholar.org/51b9/124a3d04b4479dbab065b7bc58088a86dbfa.pdf

Maleae intergeneric hybrids:  https://en.wikipedia.org/wiki/Maleae

Malus Pyrus (commonly known as Zwintz-scher’s Hybrid) hybrid: https://www.researchgate.net/profile/Stefan_Martens/publication/261771797_F1_hybrid_of_cultivated_apple_Malus_domestica_and_European_pear_Pyrus_communis_with_fertile_F2_offspring/links/02e7e53577214e7655000000/F1-hybrid-of-cultivated-apple-Malus-domestica-and-European-pear-Pyrus-communis-with-fertile-F2-offspring.pdf

Sorbus Pyrus hybrid: https://www.actahort.org/books/918/918_123.htm

To add more weight to the possibility of a strawberry raspberry hybrid, there are intergeneric hybrids between strawberries and Potentilla:

Fragaria Potentilla hybrid: https://www.actahort.org/books/348/348_19.htm

Now that we have demonstrated intergeneric hybrids do occur in plants (and animals), and that Fragaria are known to hybridise with closely related genera, I guess the next step it to look at my strawberry raspberry hybrid and answer some questions I have received over them.

Elongated petiolule - this is not seen in the parent species

Are you 100% certain this is a strawberry raspberry hybrid?
When attempting this cross I emasculated the flowers and bagged them prior to hand pollination.  I attempted reciprocal crosses between plants of the same ploidy to increase chances of success.  A a control I emasculated and bagged some flowers but didn't pollinate them, all aborted early and none produced seed.  I tried many crosses, planted many seeds and very few germinated, out of those most died early.  The leaves, flowers, and fruits of the surviving plant are different from the parent varieties.  Strawberry seeds planted at the same time as the hybrid seeds began flowering around 5 months old, this hybrid plant took around 10 months and then the first few sets of flowers aborted without setting fruit.  The parent strawberry throws a lot of runners from a very young age, this plant is over a year old and has not yet thrown any runners.  I have saved seed from this plant and they seem to have less than 5% germination rate, while the strawberry parent's seeds usually have over 95% germination.  Even with all of this, there is still an incredibly small chance that some tiny ant crawled in under the bag and pollinated the flower, so without genetic testing I cannot be completely certain it is a hybrid.  To answer the question: I am not certain that this is a hybrid.

Has this been independently tested and proven to be a strawberry raspberry hybrid? 
Not yet.  I would love someone to test this genetically to conclusively determine if it is a hybrid.  I don't know how to get this done in Australia.  If you are able to help please let me know.  Edit to add: I sent samples of these plants to the CSIRO who have since tested them.  They are true intergeneric strawberry raspberry hybrids.  The results can be seen here.

Unripe berry - lumpy and forked at the end

It can't be a hybrid because the berry is bumpy and ugly.  

If anything its unique looks add to the possibility that it may be a true hybrid.  This is just one of the morphological abnormalities that can be observed between this plant and the strawberry parent.  Other morphological abnormalities include the length of petiolules, flowers always being subtended by a leaf, inconsistent flower structure (such as extra petals and fewer stamens), and the absence of runners.  Germination time/percentage, early death of large numbers of seedlings, and the greatly extended time from germination to maturity are among the other factors that suggest this plant may not just be a strawberry.

This looks like a strawberry, why doesn’t it look more like an equal mix of raspberry and strawberry?  

In wide crosses there is often, but not always, asymmetric expression patterns and phenotypic similarity with the seed parent.  I am not sure why it happens in some crosses but not others.  Most of the papers I have read on this phenomenon appear to be based on interspecific crosses rather than intergeneric crosses, but there are a few papers written on triticale that suggest this strong maternal effect in intergeneric hybrids is relatively common (www.fao.org/3/a-y5553e.pdf).  So while I don't know why this happens, I know that it does happen often.

Flowers always subtended by a leaf

Some poorly worded question about fruit types eg strawberry produce achenes on a fleshy receptacle while raspberry produce drupes.

I am not quite sure what the question is here, or how this would ever support or disprove this possibly being a hybrid, so I will take a stab and try to guess what they are asking.  Usually several genes interact to create what we see in a plant or animal.  Some genes are dominant over others and if both genes are present you often only see the effects from one (ie one is dominant and the other is recessive).  The fruiting structure that we see is due to the genes present in the plant and how the genes interact with each other.  This is unexplored territory, we have little understanding of what phenotype a plant will display when it is heterozygous for fruiting in drupes and producing achenes on a receptacle.  Both parents were diploid (2n = 2x = 14) so if this is a true hybrid it and any seedlings it produces could shed light on genetic interactions that are as yet unknown.

If these are possible why hasn’t anyone done this before?  

This is one of the most common questions, it makes little sense and appears to be a self-fulfilling prophecy.  Our collective scientific knowledge in any given area isn’t as far along as people think it is.  There are plenty of things we have never attempted and all areas of science break new ground all the time.  As no one ever attempts to do this cross you assume it can’t be done.  Wouldn’t it be better if it was attempted, then proven to be possible or not to be possible?  In the past this hybrid was created using somatic fusion and the resultant plant was apparently viable, I am unsure if it fruited and have not seen any pictures of the plant.  My attempt at crossing strawberry and raspberry involved cross pollination (similar to Burbank's attempt) rather than somatic protoplast fusion.  Unlike Burbank’s attempt, I used plants of the same ploidy to increase the chance of success.  Not all that long ago crossing plum and apricot was thought impossible because no one had attempted it, today you can buy plumcots from the shops!  

 

Edit to add: I sent samples of these plants to the CSIRO who tested them and determined that they are true intergeneric strawberry raspberry hybrids.  The results can be seen here. 

Pineapple sage

Years ago we bought a small plant called Pineapple Sage (Salvia elegans).  It was amazing, my kids loved it, I loved it, and it grew well for us.

Pineapple sage really smells like sweet pineapple.  Unlike many other herbs this one did not disappoint.  It was good in herbal 'tea', it was good in cooking, it looked nice, the flowers are pretty, there was nothing bad about this plant.

For a few years I took cuttings,  we harvested the leaves, and I protected it over winter as it dislikes frosts.  It can take a few light frosts, but repeated hard frosts can kill it.

Then we moved house, and a few months later moved house again, then my wife gave birth to our youngest son.  Somehow in all the chaos we lost our pineapple sage plant.

My son loves pineapple sage tea, so I searched for another plant.  I bought one that was labelled as 'golden pineapple sage'.  It was meant to have yellow leaves, but it didn't.  It looked just like my old plant, but didn't grow very fast, and the pineapple smell was surprisingly weak.  My son adores pineapple sage tea, but he didn't bother making tea from this weak plant.  There was no point, it was too mild that it was like drinking hot water.

The plant itself was also weak, even though I protected it the thing died over winter.  It was no great loss, that plant was inferior.

Then we got another pineapple sage plant.  This one was strong and green and vigorous.  It grew fast and smelled even stronger than our first plant.  All the pineapple sage pictures on this blog page are of this stronger plant.  It was an amazing plant, I really liked it.  Look how lush it is.

Pineapple sage growing well

Eventually autumn came, so I took some cuttings to over winter away from the frosts.  I also left the plant where it stood figuring winter would kill it.  When I got around to it I would remove the twigs.  I picked a lot of the leaves and dried them to use over winter.  It was actually pretty good dried.

Frosts were hard that winter, we had snow and hail and many frosts.  All the leaves and branches died.  I had a heap of cuttings growing happily out of the frosts so wasn't terribly bothered.

Then something incredible happened:

Can you see it in the middle of that mess?

Take a closer look:

The pineapple sage is sprouting, it survived winter!

The pineapple sage plant started to sprout from its roots.  It had survived the frosts!  That was unexpected.

From there the plant grew, and grew, and grew.  I took more cuttings and grew more pineapple sage plants in other parts of the garden.  This plant just kept getting larger and providing more and more leaves. 

Look at it grow!

Pineapple sage is delightful

Pineapple sage - it grew far larger than this

Eventually autumn came again.  I meant to dry some leaves again but forgot until too late.  I took cuttings to grow somewhere safe as I never want to lose this plant.  I also covered the plant in straw to see if it would survive another winter.

This winter has been the warmest I have ever heard of in this region, so my plant is doing just fine.  The branches have dropped most leaves, but some are still hanging in there and are green.  Not surprisingly all the cuttings are looking great too.

I sell small bare rooted plants over summer, if you are interested they will be listed on my for sale page along with other perennial vegetables for sale in Australia.  I can post to most states, but do have some domestic quarantine restrictions.

The best culinary thyme variety: Jekka's Thyme

I have a (possibly bad) habit of growing new and interesting vegetables. Some things grow exceptionally well for me, other things I can’t get them to crop at all. Sometimes they taste amazing and earn themselves a permanent place in my garden each year from them on, others aren’t all that great and I decide not to grow them again.

About a dozen years ago I grew yacon, I have kept dividing the same plant since then and have brought it with me as I moved house time and time again. I grew some skirret years ago and it has earned a permanent place in my yard, I can’t recommend this delicious and hardy vegetable highly enough.

Other things such as maca (Lepidium meyenii) I really enjoyed, but they never cropped all that well for me and couldn’t cope with the endless furnace like blasting dry heat when we lived in the Central West so I had to let them go, they may do well now I live in a cooler region again.

Some of the annual vegetables (or perennials that I grew like annuals) such as some fancy varieties of eggplant sounded great but really didn’t perform for me in my garden so have never been grown since.Others have been so great I grow them every single year.

A few years ago I tracked down a bunch of different varieties of edible thyme. I wrote a blog post comparing thyme varieties and showing pictures of their leaves near a ruler for scale. They have all grown well for me, and I am rather fond of most of them, but one variety of thyme in particular is far more vigorous and useful than any of the others.

Jekka's thyme forming a dense carpet

Jekka’s thyme was bred by a well-known herb breeder by the name of Jekka McVicar. I can understand why the breeder would want their name associated with such an outstanding variety. I believe Jekka's thyme won a bunch of awards at various horticultural shows, I would try to list them but really don’t think they mean a great deal. I have a feeling that winning these awards often has more to do with marketing than with the quality of a plant, I have bred some remarkable new vegetable varieties but wouldn’t know how to even enter these competitions.

Jekka's thyme smells and tastes strongly of thyme, which is the main reason I grow thyme. Plants produce comparatively large leaves (for thyme), and even without trimming they produce a lot of them. Most of the larger leaf varieties of thyme seem to struggle in the heat far more than the smaller leaf varieties. Jekkas thyme grows rather dense and casts a lot of shade on the soil, which appears to help it stand up to the heat surprisingly well for a larger leaf variety. Like most varieties of thyme they respond well to regular harvesting.

Jekka's thyme on the right (tabor thyme on the left)

One thing that surprised me was how fast and dense Jekkas thyme grows, they grow into a thick blanket of leaves and branches which cover the soil surface completely. As it is so thick, Jekkas thyme could probably be grown as a deep living mulch around taller plants or container grown fruit trees. I have a feeling that this would work well in pots long term.

Like most varieties of thyme they flower well, and the flowers are moderately attractive to honey bees and various native pollinators. The flowers look and smell like the flowers of most other varieties of edible thyme – dense clusters that are pink and tiny.

Jekka's Thyme Flowers

One thing I particularly like about this variety is how fast and how far Jekka's thyme spreads. They grow faster than any other variety I have grown, they are reasonably low growing, and any node that touches soil seems to set down roots quickly. The plant can be cut at this point and the new plantlet dug and moved, or it can be left where it is to keep expanding. Like most varieties of thyme they also grow easily from cuttings. Jekkas thyme seems to grow a lot faster than any other variety I have seen, I have one patch that has spread more than a meter and a half from the original plant in one single year!

Frosts down to about -10 do not appear to bother Jekka's thyme, it doesn’t really get colder than that here so I can’t comment about its survival in colder temperatures.

Jekka's thyme in the frost

People sometimes ask me about fertilisers and so forth. Honestly I can’t provide advice with that as I don’t use them. I fertilise when I prepare the garden bed by digging in homemade compost or manure from our animals. I water these plants over summer, and sometimes remove weeds, but that is all. I have never seen any pest or disease issues, I assume these issues can happen with Jekka's thyme but I haven’t encountered them yet.

In my opinion Jekka's thyme is a superior variety.  The only difficult part about growing Jekkas thyme is actually finding plants for sale.

Please don’t ever waste your money on seeds of Jekka’s thyme as they won’t grow like the parent. Most will be smaller and less vigorous, some may almost be as good as the parent. You are better off buying a plant as you will be sure of its quality.

I sell small bare rooted Jekka's thyme plants (or vigorously growing rooted cuttings depending on timing) and can post them to most of Australia. If you are interested they are listed on my for sale page along with other perennial vegetables, edible herbs, and heirloom vegetable seeds.

Since writing this post, I have written another post on Jekka's thyme in which I show comparison photos between it and regular garden thyme.  The difference in vigour, size of leaves, and amount of leaves is rather impressive. 

Tomato Breeding

One of my favourite tomatoes is Japanese Black Trifele (spelled a few different ways).  They taste amazing, they usually crop heavily for me, they taste great, they are reasonably quick to mature, and did I mention they taste great?  They are one of the varieties I grow every year.  I really like them, but find they they are a bit small for my liking.

I can't grow every tomato variety I have every year so I have a bit of a rotation to refresh my seeds.  Some varieties are very good, but not good enough to be grown every year.  Another great tomato variety I grow some years are a much larger fruited tomato, they taste great, they usually crop well, but the tomatoes are a bit too large for my liking so don't get grown every year.

• Question: What would happen if you cross one of the best tasting tomatoes that is a touch too small (such as Japanese Black Trifele) with a great tasting tomato that is much larger? 
• Answer: You get an amazing tasting tomato that is just the right size (as well as a whole heap of other tomatoes of different sizes, some taste better than others).

This new tomato has an interesting colour, this year it had regular leaf but it may or may not still have recessive potato leaf genes because I have been selecting taste/size of fruit and ignoring all other traits.  Unfortunately I didn't take a photo of it sliced, the colour inside was dark and amazing.  I hope when I have stabilized this variety it retains this rich colour.

This year was a dreadful year for tomatoes in my garden.  Many varieties did not crop at all, some only provided 1 or 2 tomatoes, some gave very small crops.

This new tomato was one of the first to ripen, being so early in the season I thought nothing of eating them as I figured that I would save seed later in the season.  Then the heat or something hit and I only saved seed from one or two fruit.  I wish I had more seeds, but I have what I have.  This isn't great, but it will have to do.

Great tasting tomato - top

Great tasting tomato - side

Great tasting tomato - bottom

Assuming all goes well, it will be a few years before this is a stable variety.  Stabilising a tomato variety usually takes 7 to 10 generations, sometimes more.

Stablising a variety can be done in a year or two if you play around with double haploids, but I don't think I will do that for this variety.  I plan to grow a few of them next year and continue to select the best ones.

My aim is to produce tomatoes that fruit like this one.  They are the right size, they look nice, they are soft, they smell nice, they crop well, and most importantly they are absolutely delicious.  Everything else, such as fruit colour, leaf shape etc, are not really important.

I sell seeds of a few heirloom tomatoes through my for sale page.  I likely won't offer seeds of this one for a long time as they are not even close to being stable.

Wasabi herb

A few years ago I bought a small edible herb that was called "wasabi salad herb" (Diplotaxis erucoides). Apparently there are a few other herbs with the common name of “wasabi herb”, in this blog post I am only referring to Diplotaxis erucoides.

This is not real wasabi, this is an edible leaf herb that is far simpler to grow than wasabi, it tastes kind of similar to wasabi, gives a similar nose tingling feeling as wasabi, and it lacks the extreme heat of true wasabi so is easier to eat.

Wasabi herb - Diplotaxis erucoides

Wasabi herb is not particularly rare, many online places have seed for sale and it is dreadfully simply to grow from seed, yet for some reason few people tend to grow them.

I wrote an earlier post saying how happy I was with it at the time. I have continued to grow this since then and have learned a few things so thought it was probably time to write another blog post.

One of the least important things I have learned is this wasabi herb is not a true annual. Some of my wasabi herb plants did flower and die, others flower and stay alive to produce leaves and more flowers for another year or two. I have one of the original plants that is still alive and flowering. We often call things like this annuals when they really are short lived perennials. This annual/perennial distinction is not as black and white as we often pretend it is. It also doesn’t really matter as most people will grow these as annuals and kill plants after they flower and set seed.

The time from seed to the first leaf harvest is rather short. Unfortunately I have not recorded it. I record when I plant seed, then I forget until it has been flowering for a few weeks. In the heat of summer, or if transplanted, they will bolt to flower quickly. Over cooler months they will produce leaves for a lot longer.

Wasabi herb flowering, you can hear it humming from all the bees

While wasabi herb does not love the heat, it seems to grow well over the cooler months. I am happy to say that wasabi herb is not damaged by frosts. We get hard frosts here and my plants seem un-phased by it. Some will flower while it is frosty which is a really great trait to have.

Honey bees, and several native pollinators, adore wasabi herb. It produces plenty of nectar and pollen (I have read that its pollen contains 23% – 24% protein which is slightly higher than most of the pollen they collect) and flowers in such profusion that it must make collecting resources a lot easier for little insects.

I have grown many flowers that are supposed to attract bees yet rarely ever see a bee on them, wasabi herb really does attract bees. While it is flowering, if the weather is good for bees to be out foraging, I always see numerous bees working it. I have seen other flowers only worked by bees if nothing else is around, but wasabi herb is one of their absolute favourites.

Another favourite where I always see bees is the poppy, which does not produce nectar but its pollen contains over 40% protein! Honey bees madly work poppies in the morning, once all the pollen has been collected they are of no interest to the bees and they move on to other things.

Wasabi herb, one of the bee's favourite flowers

If seeds are scattered every few weeks or months you end up with a self-sustaining patch of wasabi herb plants of varying ages that flowers almost all year. Each individual plant won’t flower all year, but some of the plants in the patch will be flowering at any point in time. This means that bees always have a high quality food source nearby.

I have grown wasabi herb in the vegetable garden, where it performs at its best. I have allowed seeds to fall among the lawn, where it grows and flowers as long as you don't mow too often. I have also scattered seeds among roadside weeds that are rarely mown to see if it survives there, I am waiting to see if it establishes itself there to permanently provide resources for the bees.

 

Wasabi herb - Diplotaxis erucoides

I keep meaning to collect enough seed to be able to sell them, but every time I save some seed I seem to give it away to people who need it.  If I ever do have enough seed to sell I will list it on my for sale page.  Failing that there are many seed sellers who carry this little gem, just be sure to use its binomial name (Diplotaxis erucoides) when searching as common names are a bit confusing.

Graft hybrid attempt

Graft hybrids are a topic of much controversy, has been studied only briefly, and at this point in time the concept is very poorly understood.

For years it was believed that DNA did not cross the graft union further than a few adjoining cells, then it became clear that metabolites and some DNA could cross the graft union but there was controversy over how far this would travel or if any changes could be inherited by seeds.  Then it started to look as though DNA transfer can be heritable and passed on through seeds to some extent.

While there is still a lot of controversy over this topic, it is now pretty clear that DNA can cross the graft union under some situations and may cause heritable changes to be incorporated into seeds.

Graft hybridisation is not the same as cross pollinating where half of the DNA from each parent is passed on.  We are not sure how much DNA from each parent is passed on, and it appears in many cases that 0% is passed on.  At the moment there are more questions than there are answers.  I find it fascinating.

Cross pollinating strawberry and raspberry to create a hybrid has a low rate of success and is rather time consuming.  I can see why so few people have ever attempted this.  Around two years ago I made a large number of attempts, planted large numbers of seed, and only have a very small number of fruiting intergeneric hybrid plants to show for my efforts.

Given that heritable changes to DNA can sometimes be incorporated through grafting, it got me thinking.  Perhaps it is possible to use graft hybridisation to cross strawberry and raspberry plants?  Perhaps I graft the two, allow the scion to flower/fruit, collect the seeds, if I plant the seeds they may display some form of genetic cross over between the two plants.

To attempt this, the first question is one of what part to graft.  It may be possible to graft the growing tip of a raspberry onto strawberry roots, I am self-taught at grafting and that sounds difficult.  I worry that I am not up to this kind of grafting and would likely just kill both plants.  So this may not make crossing the two any faster or easier than simply cross pollinating a lot of flowers.

Or, would it be best to graft strawberry scion onto a raspberry plant?  Some strawberry plants can go from seed to fruit in 5 months or less, saving and germinating strawberry seeds is simple.  I guess it is possible to excise the strawberry’s growing bud and graft that to a raspberry somehow, again this sounds like a difficult graft for someone with few grafting skills, so I would probably end up killing both plants.

Assuming that it is even possible to graft a rasberry and a strawberry, this graft may or may not take all that easily as there may be issues with mild incompatibility.  I am self-taught, and don’t have a laboratory, so will be working in the field where insects and birds and children frequently visit and the weather can be downright hostile at times.  If I have any hope of succeeding I need to work with something that is simple to graft to increase my chances of success.

Strawberry runners grafted onto a raspberry cane

I decided to try and graft strawberry runners onto a raspberry cane.  Runners give me a large area to work with so if I mess up I can cut off that part and try again, I can do this several times if needed, until I make a neat cut on just the right angle.  You can't really see in the photos, but some runners are long and others are short, this was partly to see if that made a difference and partly because I had to cut some runners shorter as I made the cut wrong a few times.  I did this with a few plants but only took pictures of the first one.

With runners the young plantlet is still developing, if grafted onto a more mature raspberry cane it will be a kind of ‘mentor graft’ which is said to facilitate DNA exchange.  Given the length of a raspberry cane I can graft large numbers of runners and increase the chances of one working. I ended up grafting more than is in the photographs, about half a dozen runners per raspberry cane.  I wanted to do more but ran out of time and effort.

I grafted several strawberry runners onto a few raspberry plants.  I am unsure if ploidy makes any difference to success rates of grafting two different genus so I used both diploid plants (2n = 2x = 14).  The runners were very thin and difficult to use, but it was all I had available at the time.

To the best of my knowledge, no one has ever attempted anything like this using strawberry and raspberry.  There have been a few attempts using various Solanaceae species that have confirmed genetic material can cross the graft union and these changes can be heritable in the seeds, and at least one intriguing graft hybrid experiment using plums, but nothing with Rubus and Fragaria.

My plan was to graft strawberry runners onto raspberry canes, then when the strawberry plant was large enough I would allow it to root in soil.  Potentially some raspberry genes may have crossed into that strawberry and may be heritable.  I would then allow that strawberry (which had previously been grafted onto a raspberry) to flower and set fruit, I would collect and plant seed, and then see if there were any noticeable difference in those seedlings.

I assumed that if this worked there would be a low rate of genetic cross over, so I was planning on growing out a lot of seedlings.

I ran out of time on grafting day and kept some of the runners not grafted but sitting in a glass of water.  They all died after a day, so gave me hope that my poor technique grafting may have been successful.  All of my grafts looked bad for a day or two, then they perked up.  This was a very encouraging sign.

After 8 days there was a preventable mishap.  One hot day most of my strawberry raspberry grafts died.  The plants were in a plastic bag to increase humidity, but it also made a little solar oven which cooked them.  They looked fine in the morning, and were crispy and dead in the evening.  I think it was due to the heat rather than incompatibility issues as the raspberry hosts dropped a lot of their leaves that day.

After that incident I had one single grafted runner that was still alive and growing well.  It was small but growing fast, so I assumed the graft had taken.  This runner had a small plant that then sent out a further runner, so I was confident this had worked.  This grafted runner remained alive for 28 days after the initial heatwave and was developing well, I put a pot of soil under it so it could send down roots, then another heatwave hit and it died before it had a chance to root.

My little strawberry runner survived for 36 days after I had grafted it and had a nice looking little plant ready to set down roots.  This was extremely frustrating.  The rest of summer was record breakingly hot so I didn't try again.  I even lost a lot of my raspberry plants that were growing in the garden.

I hope to give this another try in spring if I have time.  The fact that the last runner lived so long was encouraging, but at this point I don't know if this could work, let alone if my grafting skills are good enough to succeed.  Unfortunately either no one has tried this before, or they haven't bothered making their results accessible, so I will have to do it and learn for myself. 

If I give this another try I plan to write a blog post of the results.  Even if I am unsuccessful it is a good result and worth learning from.  I wish someone else had tried this properly and either failed or succeeded, that way I wouldn't have to start from scratch.  Let's be honest, if this is not going to work then I am just wasting time.

Helsing Junction Blue tomato

For a few years now (ever since they mysteriously made their way into the country) I have been growing different varieties of high anthocyanin tomatoes.

High anthocyanin tomatoes turn dark blue to black where the sun hits them. Unlike the old heirloom varieties that were called black but were really a muddy brown, high anthocyanin tomatoes actually can be black.

Anthocyanins are a group of powerful antioxidants, darker varieties contain higher concentrations of these antioxidants so are presumably even healthier to eat than regular tomatoes. The early high anthocyanin lines such as ‘OSU blue’ were incredibly black, but didn’t taste all that amazing. Sadly they didn’t taste all that much better than store bought tomatoes.

These early released black varieties have been used in breeding efforts to create tomatoes that are black and also taste good, huge improvements have been made in this area and some of the more recent released high anthocyanin varieties are starting to taste pretty good.

Helsing Junction Blue tomato - not ripe yet

I have been growing a tomato called Helsing Junction Blue (or Helsing Junction Blues, I am unclear if it has an ‘s’ on the end). This variety is said to be bred by Tom Wagner and named after the Helsing Junction Farm in the Chahalis River Valley, Washington state. Normally I am not a fan of Tom Wagner’s tomatoes (other than a tomato named Verde Claro, which is truly exceptional), and normally I am not a huge fan of high anthocyanin tomatoes (although many of the newer varieties are actually really good), but this one yields well and tastes great.

Helsing Junction Blue grows into a tall and vigorous plant with regular leaf. It is an indeterminate variety, meaning it will fruit all season long until killed by frost, or can be grown as a perennial if protected from frosts. Being tall means they will need some form of staking or they will sprawl and cover a lot of space. Like many indeterminate varieties it is incredibly simple to grow from cuttings.

For me Helsing Junction Blue produces high yields of large cherry tomatoes over a long season, they are sweet and have a decent rich taste for a black tomato.

Early in the season this variety looks like any other, you can tell it is high anthocyanin as the stems get a purple tinge to them at times. Its flowers and unripe green fruit are round and look unremarkable.

Before the fruits ripen they start to turn purple, bright purple, it is almost unbelievable the purple they turn. I really wish they stayed this colour when they were ripe, but they don’t.

Helsing Junction Blue unripe fruits

Not ripe, but they look great!

Eventually they start to ripen, places the sun does not hit turn red, and anywhere that is hit by the sun turns black with red underneath. Higher exposure to ultraviolet light makes them darker, and strangely enough cool temperatures combined with high light intensity enhances the dark colouration.

This means that fruit produced in autumn is noticeably darker than fruit produced at the height of summer. It is only the skin that is black, inside the flesh of this variety is red.

Helsing Junction Blue - ripe fruit

Helsing Junction Blue, they do get much darker black than this

Once they have started to ripen you end up with a large plant covered in fruit from unripe to ripe, ranging from green, to an interesting purple, through to red and black.

I have had people stop and stare at my plants and ask me questions, bewildered that such interesting colours can actually be real. People always want to eat a bright purple ones, I try to explain that purple are not ripe and the black and red ones are ripe. They taste those and like them, but are always a little disappointed that I won’t let them eat the unripe purple ones.

People want to eat the purple ones, but they aren't ripe yet

Helsing Junction Blue tomatoes have a nice, reasonably rich taste, and are pleasantly sweet. I have never cooked with them by themselves so can’t comment on that. We have frozen them in with other tomatoes and cooked with them all mixed together, the results vary but the number and composition of varieties of tomatoes included in these frozen packs also varies considerably.

Being a cherry tomato means they are often eaten whole and are good used in salads. My kids happily pick them and eat them from the plant whenever they walk past the plants and I am not watching. Yeah, they think they are being sneaky but I know they do this, I just don’t try to stop them because they know not to pick the ones with string that were used for breeding and/or isolated for seed saving.

I recorded Helsing Junction Blue as taking 166 days from planting the seed until picking the first ripe fruit (this is often referred to as 60 to 70 days by most seed sellers, but they don't start counting until transplant).

Towards the end of the season when the weather cools the fruits looks its darkest, and the stems take on more purple colouration. No tomato tastes its best when ripened in cool weather (or if ripened in warm weather but then put in the fridge for a few hours – seriously why do people ever do that), and Helsing Junction Blue is no exception. I have never been overly impressed with the taste of any variety of tomato that ripened when the weather was cold.

Some of my plants flower through light frosts, then they start to produce flowers and fruit that are odd. I don’t know how to explain, some fruit are almost like they are inside out. Some of the flowers look like they produce fruit before the flowers open and had no chance to produce pollen.

I don’t know if they are parthenocarpic and set fruit without pollination or if something else is happening here. I have never had these weird fruit ripen as heavier frosts kills them off first, so I don’t know what they will look like or taste like or if these late fruits contain any seed. I assume these oddities are caused by the cold temperatures, perhaps it is a trait from one of the wild species that was used to breed in the dark colour.

Fruits forming before the flowers even opened

Anthocyanin concentrating in the leaf tips during high UV and low temperatures

Weird fruits forming before the flowers opened

Based on their taste, yield, resistance to disease, and impressive looking fruit I am pretty happy with Helsing Junction Blue tomatoes. I don’t grow them each year as I have far more varieties than I can fit in the garden in any given year, but they are in my rotation to be grown every two or three years.

 I sell seeds of several varieties of tomato as wel as a bunch of other perennial vegetables and herbs on my for sale page.

Male vs Female Asparagus: Which Produces the Better Harvest?

Asparagus (Asparagus officinalis) is a perennial vegetable that is dioecious, meaning that individual asparagus plants are either male or female (or sometimes they are 'super male', but that is a topic for another day). There aren't a huge number of dioecios vegetables, which makes asparagus interesting.

With asparagus you want many long and fat dense spears that are not fibrous, when they start to become thinner you stop harvesting for the year. It is common advice to remove/kill all female plants as the males are said to provide larger yields of fatter, longer, and better quality spears. It is common advice that female asparagus produce thin spears so can be weeded out early.

But is this really true? I have never met anyone who has tested this theory, have you?

 

I have always wondered if this was true or just another garden myth that people spread about. I used to have heaps of seed grown green asparagus plants scattered through our orchards, some produced fatter or longer spears than others. I never noticed any difference between the males and females.  But these grew from seeds deposited by birds, and were various ages, and none of them were watered or weeded, so you can't really draw any sensible conclusions from that.

I also had a female purple asparagus plant that used to grow the fattest and most succulent spears I have ever seen. Perhaps that is a variety trait and male plants of the same variety would be even better? 

I wanted to do a comparison to see if this is the case, but I lack the necessary resources to run a trial properly. As I could not run this trial to get this information myself I looked up some peer reviewed papers, and the results were really surprising.

Female asparagus producing long fat straight spears

Firstly there were a bunch of papers claiming that certain all male F1 cultivars (or 'male dominated' F1 cultivars) out yield traditional heirloom varieties that have both male and female plants. That is nice, and useful information for commercial production. This wasn't surprising, many F1 vegetable hybrids out yield tastier heirloom varieties. I want to compare the yield and quality of male to female of the same variety, not just comparing one variety to another. I am also interested in quality, not just quantity.

I found a few papers published in 1909 saying that all male asparagus fields provide higher yields than mixed fields. After reading though the methods it sounds like the mixed fields had issues with competition (from seedlings) rather than being a direct comparison between male asparagus and female asparagus plants. Again this is useful for commercial growers, but not all that useful for home growers with small numbers of plants.

Purple asparagus

So I kept looking and I stumbled across a bunch of papers, some published recently and others were far older than I am, and they compared male to female asparagus plants of the same variety to one another. Some papers focused on just one variety, others focused on multiple varieties, and they all had similar trends.

I will provide the full abstract of one of these papers, and then use sentences from others to highlight the findings.

 

Comparison of spear yield and quality between male and female asparagus plants in protected mother fern culture (https://www.ishs.org/ishs-article/1223_24)

"A higher yield of spears is generally obtained from male asparagus plants than females in outdoor culture. However, recently in Japan, it was reported that the spear weight and yield of female plants was generally greater than those of males in rootstock-planting forcing or mother fern culture. 'UC157' plants were grown in large black polyethylene pots. Spears were harvested daily and their weight and external appearance were recorded for four and two years, respectively. Spear numbers were not significantly different between male and female plants in spring, and tended to be greater per male plant than per female plant from summer to autumn. Mean spear weights per female plant were significantly higher than those per male plant in spring and from summer to autumn. Spear yields per female plant were also significantly higher than those per male plant during spring, whereas no significant differences were found from summer to autumn. Spearhead tightness, an important external quality indicator, was significantly better in female plants than males. From these results, we concluded that in spring, the spear yield and quality of female plants would be better than those of male plants without causing a difference in the annual yield. Therefore, a choice of all-male varieties seems to be not necessary and all female cultivation could be profitable for protected mother fern culture in Japan, since the price of spears in spring and heavier spears is higher in the Japanese asparagus market".

 

A large scale experiment which compared male and female asparagus plants from several varieties published in 2016 said: 
"The results of this study show that the female plants had a significantly higher rootstock weight, weight per spear per plant, and weight per early spear per plant, whereas the male plants had a significantly higher total spear number per plant, early spear number per plant, and significantly fewer days to first harvest".

Another paper said: 
“With the average stalk diameter there was no difference between male and female plants in 1964; in the first two years the diameter of the female plants was larger than that of the male”.

Yet another paper stated: 
“Female plants had higher stalks and longer length to primary branch than male plants”.

Another paper states: 
“…highest number of very thick spears appears generally in female plants”.

 

This is all incredibly interesting, it means that female asparagus plants do not necessarily produce fewer spears in spring (when I am harvesting them), or thinner spears, or spears of lower quality than male asparagus plants. 

If anything these papers demonstrate that female asparagus plants often produce fatter, longer, better quality spears while males tend to produce more spears that are shorter, thinner, and of poorer quality.

Female asparagus producing berries

Knowing this, the first thing you do is ask why we have always been told to remove and kill all female asparagus plants.

 

I believe this advice is mostly due to female asparagus’ incompatibility with large scale commercial production, and partly due to the extra work required to look after them for home gardeners long term. 

Male asparagus plants flower and then the flower falls off, female asparagus plants flower and produce little red fruits that are filled with seeds. In time the female asparagus plants drop their fruit, the seeds eventually germinate and the bed gets choked with too many plants, leading to a reduction in quantity and quality of yield. Sometimes birds eat the berries and deposit the seeds in concentrated places causing a bit of a weed issue.

For a commercial grower with acres of asparagus this would be devastating and costly/difficult to overcome. Spraying a pre-emergent herbicide to prevent seedlings from growing sounds like extra time and money being spent, growing only male plants would be better in this situation. 

In a commercial scale, producing many thin spears often results in higher profits than growing fatter, longer, higher quality spears. Remember that people in cities need to eat, and commercial agriculture must focus on profits and feeding landless people. If they didn't we would have massive famines in the city. Commercial agriculture must focus on producing large quantities of food that people can afford, often this is done at the expense of quality.

Commercial asparagus growers tend to want thin spears. I have even seen certain asparagus varieties described as having thick spears, and then recommending planting closer than normal so they will produce thinner spears.

When growing food in the back yard can focus on quality.  Quantity is nice, but when home grown it comes second to producing high quality food.

Asparagus surviving the heat and dry

For a home grower with a small number of plants who is growing for personal consumption rather than profit, this news is not so gloomy. In the long term they either need to remove all the berries, or carefully dig up and transplant the seedlings, otherwise the bed gets choked and only thin spears are produced. On the other hand, as a home grower with few plants it isn’t too hard to pull the berries off and sow them somewhere, providing you with extra asparagus plants to either keep or give away. So this extra work actually becomes a positive. 

According to the literature above, female plants often produce longer, fatter spears of higher quality. These are exactly the traits that I want when growing asparagus!

If you are growing food at home you may as well grow the best. I am not growing asparagus to sell the spears, I am growing to eat them. So if the choice I have to make is either more spears that are thin and low quality, or less spears if they are fatter and of superior quality, I will choose the latter every time.

Commercial Asparagus Growers Vs Home Growers

Research often focuses on maximising commercial yields, where producing more marketable spears can improve profitability.  Home gardeners, however, may value different things, such as larger spears, preserving older varieties, tastier varieties, or simply enjoying a productive asparagus bed.  For that reason, I don't think female plants should automatically be removed from every home garden

Factor	Commercial Growers	Home Gardeners
Main goal	Maximum yield and profit	Fresh, high-quality asparagus for the family
Preferred plants	Mostly male hybrids	Male, female, or a mixture
Number of spears	Higher spear production is preferred	Less important than overall eating quality
Spear size	Uniform spears are preferred for sale	Larger spears may be preferred, even if fewer are produced
Seed production	Undesirable because it creates volunteer seedlings	Usually easy to manage by removing berries or unwanted seedlings
Maintenance	Reducing labour saves money	A little extra maintenance is rarely a problem
Plant breeding	Modern all-male hybrids are common	Older varieties and mixed plantings work well
Best choice	All-male varieties often make the most economic sense.	Choose the plants that best suit your garden and priorities.

Asparagus growing between QLD arrowroot

Frequently Asked Questions

Are female asparagus plants worth keeping?

Yes, for many home gardeners they are.  Although male plants often produce more spears, female plants often produce larger, heavier, more succulent spears depending on the variety and growing conditions.

Why do commercial growers prefer male asparagus?

Female plants produce berries and seedlings, increasing maintenance, while all-male hybrids often maximise marketable spear production.

Can I grow both male and female asparagus?

Absolutely.

Many home gardeners do exactly that.

Final Thoughts

Personally my plants are all seed grown and I just grow whatever. I have a mix of male plants and female plants and I normally remove the berries. 

 

I have grown asparagus from seed, it takes a lot of time and effort so most people prefer to buy dormant crowns. I have been reluctant to sell seed grown asparagus as (unless I grew an "all male" F1 hybrid) a mix of male and female would be produced and I wasn’t sure if the female plants were worth it. I certainly don’t want to sell low quality plants. 

Now that I know more about the quality of female asparagus plants, and why we are told to remove female asparagus plants, I plan to get some seeds of a few heirloom varieties to grow them out and offer year old crowns for sale.  

Keep an eye on my for sale page I often have a few crowns of heirloom asparagus varieties for sale, and regularly have purple asparagus seed.