Giant Broad Leaf Dandelion

I have been breeding dandelions (Taraxacum officinale) for a few years.  Not just deliberately growing them, but intentionally breeding with the aim of improving them.

Given that every part of this remarkable plant is edible and useful, I mostly focused on breeding for larger leaves.  I also grow pink dandelions (Taraxacum pseudoroseum), I have not done any breeding work with pink dandelions and given how difficult it is to work with them I like never will.  

Giant dandelion leaf 47cm long

Breeding dandelions is difficult, I find it far more difficult than other vegetables.  

The 'flower' on a dandelion plant is hundreds of tiny flowers crammed closely together.  Individual dandelion flowers are tiny.  All parts of the flowers are tiny and are very difficult to work with.  Emasculating flowers to prevent self pollination is difficult as they are tiny, and not always effective as they can produce seeds through apomixis without any pollination.  Due to apomixis, when cross pollinating I have no idea if the cross worked, or if the resultant seed will be a clone of the mother plant.  Adding selective pressure does not always cause genetic drift, again this is due to apomixis.  

Further complicating dandelion breeding is the fact that most dandelions are triploid, and most dandelions in Australia are usually sterile triploids that reproduce by obligate apomixis.  

Unfortunately, while I understand the theory of this, I don't have a good understanding of what this means in practice.  There has been some research into dandelion ploidy and breeding, which I found interesting.  This research indicates that while it should be theoretically impossible to breed using triploid dandelions, it is experimentally possible.  

While there was a concerted effort to breed dandelions, there is very little literature on how to breed dandelions.  Most of this was written by the Soviets, is poorly translated, and largely deals with Taraxacum koksaghyz and breeding it for rubber yield.  

I believe there were a few dandelion farms in Tasmania and Western Australia.  Like much of this country's past, this seems to have been largely forgotten and lost to history.  I wish I could get hold of T koksaghyz, perhaps some day I will track down someone who has seed that they are willing to share with me.  

For these reasons I gave dandelion breeding my best shot, hoped it would work, and figured nothing useful would come of it.  I am happy to say, my breeding efforts yielded impressive results (and at the same time was kind of pointless).

These dandelion leaves grow wide

When starting to breed dandelions I focused mostly on length of leaves as this is simple to measure.  Dandelions produce longer leaves in certain seasons, and under certain growing conditions, so I had to be careful to 'compare apples with apples'. 

Dandelion grow out - leaf comparison

I have a good line in which mature plants consistently produces leaves around 50cm long.  This was a good start.  I considered leaving it there, but my plants weren't as useful as I wanted them to be.  

I had a few plants that produced leaves that were not quite as long, but were wider at certain times of the year.  These are probably more useful as a vegetable.  More leafy and less stalk.  I wondered if I could work with these wider plants, and make them even more useful.  So I (somewhat begrudgingly) did some more breeding work with them.  

Giant dandelion on left, regular dandelion on right

After a lot of fiddly work, most of which yielded exact clones of the parent plant or no seed at all due to rough handling, I started to see some progress.  This encouraged me to do a little more work.  

Again my efforts were largely frustrated by either aborted seed or exact clones of the parent, but among them were some successes.  I am certainly no expert in this area, and my results were patchy at best.  After quite some time my giant edible dandelions are incredible.  

The leaves of my dandelions often measure 6 to 7 inches wide, and are usually a little under 50 cm long.  In winter the leaves are smaller, if they don't have enough water they are smaller, and if shaded they can grow a little larger.  

Dandelion leaf over 6 inches wide

These larger wider leaves are great.  They are far more useable in a salad, or easier to feed to animals.  While I haven't tried it, I assume they could be used to wrap food similar to grape leaves or mulberry leaf. 

I am not keen on how bitter raw dandelion leaves can be, these large broad leaves taste milder and much less bitter.  Dandelion leaves tend to be less bitter before flowering, and become increasingly bitter as the plant flowers.  These giant broad dandelion leaves are pretty mild even when in bloom.  I didn't select for this trait, it was just a nice surprise with the giant plants.  

These plants need more water than lawn weeds if they are to reach their potential.  Regular lawn dandelions don't cope in the dry, these giant broad leaf dandelions really don't cope being very dry.  They tend to survive being dry if they are well established, but the resultant plants are a mere fraction of the size of what they could have been.  

Being so large, these plants need room to grow.  When grown in a pot they are always stunted.  When grown in the garden their roots can penetrate deep in search of nutrients, and they grow far larger.  They survive surprisingly well with competition, but grow a lot larger and faster if you remove their competition.  

I don't think it comes as a surprise to anyone that fertile soil is needed for them to grow large.  Poor soils result in much smaller plants.  

Dandelion leaf over 6 inches wide

These massive dandelions also seem to suffer from a leaf disease from time to time.  This disease produces spots on the leaves, it is possibly some form of leaf rust fungus.  I see this appear on regular dandelions from time to time, but it seems to affect the giant ones far more.  

Dandelion leaf spot

I am sure you could spray with something to control this.  I grow everything organically, so I am not sure how to prevent this disease, all I know is if I leave the infected leaf alone the disease will spread to other leaves.  When I see this disease I remove infected leaves and feed them to the guinea pigs or chickens, this seems to stop it spreading.  

I don't put the infected leaf in the compost for fear it will produce spores and spread, feeding it to an animal seems to destroy the pathogen.  The plant grows replacement leaves and is healthy once the spotty leaf has been removed.  This indicates that the disease is not systemic.  

Dandelion leaves over a foot and a half long

Growing dandelions from seed is simple.  They germinate best when fresh, and germination rates seem to decline quickly as seed ages.  I find light improves germination, so I plant dandelion seed much like lettuce seed.  I plant them in pots or trays of soil, and press seeds into the mix and water in.  From there I treat them the same as I treat lettuce.  

I tend to sow the seeds reasonably thick.  Dandelion seedlings start out small.  I let the seedlings grow a while before transplanting them somewhere in the garden.  Once transplanted, they need a lot of water to become established, other than that I treat them like any vegetable.  

Dandelion seedlings

Dandelion seedlings larger and ready for transplanting

After several years and an absurd amount of effort, I now have good lines of giant dandelions.  They are so large that when people see an individual leaf they often ask me what they are, and do not believe me when I explain they are dandelions.  

I do sell seed of these giant dandelions, as well as pink dandelions, through my for sale page.  The flowers were open pollinated, but there is a good chance they will produce plants that are clones of the mother.  If they were somehow pollinated by another plant, they will have 50% genes from the mother plant and should still grow huge.  If you are interested, everything I have for sale will be listed on my for sale page.