Persicaria hydropiper Water Pepper

For a few years I heard about a plant called water pepper, Persicaria hydropiper, it is also called smartweed.  I almost bought seeds, but they sold out a few yeas ago and it hasn't ever come in stock again.  

This plant looks superficially a lot like Vietnamese coriander (Persicaria odorata), but lacks the dark smudge.  Unlike perennial Vietnamese coriander, water pepper is an annual.  

According to the Victorian Department of Agriculture, this plant 'may or may not be native to Australia'.  I think that means it is growing in a lot of areas, isn't causing any harm to anyone, and it has been there for so long that they don't know if it is native or introduced.  

Persicaria hydropiper - Water Pepper

After impatiently waiting for seed to return for sale, I found some plants growing near a river.  There were a few large clumps of this plant.  All of them were near water, but none were underwater and none were growing as emergent plants.  

I took two small cuttings and brought them home.  Much like Vietnamese coriander, the water pepper was simple to grow from small cuttings.  I didn't want to disturb the local population and figured two small cuttings would be the least invasive way for me to grow this plant.  

I wanted two cuttings just in case it needed a second clone in order to set seed.  In hind sight I could have taken a few plants without making any real difference to that population, but the cuttings worked for me.

I did a lot of research before tasting this plant to make sure it was the correct species.  There are many species of Persicaria, many look similar, and all of them are edible.  This is a relief because even had I mixed up the species I would not endanger myself by eating it.

Water pepper tastes hot and peppery.  Apparently it was one of the plants used in Europe as a pepper substitute when pepper and other spices were prohibitively expensive.  Some people say it tastes similar to horseradish or wasabi, but I find it to be unique.  

The heat in water pepper comes from a substance called polygodial.  It is kind of a cool heat, if that makes any sense at all.  I find the seeds make my tongue numb.  I like it.

Seed grown water pepper plants

My water pepper grew really well.  It liked damp soil, and grew into tall plants quickly.  I took a cutting of one of my plants and grew it in garden soil where it was not overly damp.  This did ok, but not as well as the ones that had boggy soil.

It wasn't hard to pinch out the growing points and make them branch into bushy and productive plants.  If you were harvesting the leaves you would be doing this automatically, and the more you harvest the better they would grow.  Had I wanted to, I could easily have taken many more cuttings from my plants and expanded the numbers considerably.

Given how easy water pepper is to grow, and how this is too peppery to be eaten in large quantities, I did a bit of reading if any breeding work has been done to make this more of a salad vegetable.  

It turns out there is no need for this as there are other species that lack the heat, and are already good and productive vegetables.  

I found lots of info on several different Persicaria species on someone else's blog.  One species I would love to get some day is Lady's thumb (Persicaria maculosa).  It sounds pretty incredible.

I know that Lady's thumb, and a few of the other species, are present in Australia, but I haven't been able to get them yet.    

I think Lady's thumb can be a bit of a garden weed, so no one seems to sell it.  Hopefully one day I am able to try some and see what it tastes like.  Like most Persicaria species it is meant to need a lot of water to thrive, so even if it is a garden weed it shouldn't bee overly difficult to control.  Lots of edibles, such as mint or lemon balm are weeds, I just grow them with care.  

My water pepper plants grew well over the warmer seasons.  They grew nice and tall, then flowered, and died.  Being annual plants this did not come as a surprise.  I collected some seed, and sprinkled some into the soil in the original pot. 

The seeds of water pepper are edible, and are hot/peppery.  I tasted a few, they were pretty intense.  I liked them, but collecting enough seeds to use in a meal seems a bit labour intensive for my liking.  Perhaps if I had more plants this would be faster and easer, but for now I am only collecting seeds for planting so I need fewer of them.  

Once the weather warmed, the seed started to germinate.  Germination was a bit patchy, but these seeds were not planted, instead they had been in this pot for months over winter so staggered germination was expected.  I'm told the seeds don't need stratification, and you can just plant them when the weather warms. 

My Vietnamese coriander flowers each year, and it is in the same Genus as water pepper.  I don't know if anyone has ever tried to cross the two.  I have a few projects at the moment so am not sure if that is a job for me at this stage.  

Water pepper seedlings germinating

I am tempted to go back to the place I collected the initial cuttings and collect some more cuttings from more individual plants, perhaps taste a leaf from each and take a cutting from anything that stands out.  Maybe I will see if I can find a different population somewhere else and collect a few cuttings from there as they would have a different genetic stock.  Having cuttings from a few more plants would increase the genetic diversity of my stock, which is a good thing.

Being seed grown means there should be some variation, and some ability to select for the traits I want.  If nothing else having greater diversity means if there is a pest or disease, my plants should be able to cope better.  As these were locally grown, they have already survived everything in my area and are pretty well adapted to growing here. 

Water pepper flowering - I wish I took better photos

I think water pepper is a nice plant, and would like to grow more of it.  I see very few places selling plants or seeds, which means very few people will ever have a chance to eat some of this.  

I will probably sell water pepper plants through my for sale page over the warmer months.  I may sell seed if I ever collect a lot of them, or I may just stick to plants as they grow so well.  I mostly sell perennial vegetables and perennial herb plants, but think there is a place for a few annuals like this one.