Saturday, 24 May 2014

Chinese water chestnut yield

It is about time to harvest the water chestnuts.  This year I grew them in small 10 litre buckets, it was very cheap, simple and took up very little space.  This method could even be used on a balcony as it is not only productive but if you used nice looking buckets it looks good too.  I have put details of how I grew them here.

The buckets were cheap and easy to find, I filled them with clay and manure from the property, so it was also very cost effective.  They required no weeding, no pruning, no maintenance at all other than the initial planting and then filling up the buckets with water when I was out watering the rest of the vegetables.

water chestnut corms for sale in Australia
Water Chestnuts growing in a bucket
Water Chestnut yield

One bucket was ready so I pulled the plant out and broke open the root ball in search of water chestnut corms.  There were a lot of corms in that bucket ranging from tiny to medium in size, unfortunately none of them were very large.  Most were too small to bother peeling and eating but about a dozen were edible size.  A dozen edible corms return per corm planted is not too bad considering how simple this was.

I ended up with around 127 corms from that first bucket (plus a heap that were too small to bother counting but are probably just as viable), all together they weighed around 365 grams.  That bucket also produced a decent amount of straw which I can use as mulch somewhere in the vegetable garden.

The bucket had a lot of corms squashed against the side as the plant tried to reach new ground, these corms will all grow and are genetically identical to the rest of the corms in the bucket so they can be used to grow next season's crop.  They are not easy to peel as larger and rounder corms so will not be eaten by us.

I am guessing that the other buckets will yield roughly the same in terms of weight.  I have high hopes that one bucket in particular will have less corms, but they will mostly be larger corms.  That bucket was not started off with planting a corm like the others, instead I had a spare bucket of soil so I broke off a runner from one of the other plants and put it in there.  I think that it will have produced less corms and they will all be a bit larger.  When I harvest that bucket if it is any different and I remember I will try to write a comment or another post.

All of those small corms are great as it means I have plenty of stock to plant next year and to feed to animals, but I would prefer to have a lot less corms all of which are much larger. 

Water Chestnut corm

How much did it cost me

Normally I don't do this but I thought I would write the cost of this little water chestnut growing experiment.  One water chestnut corm $2, one bucket $0.85, soil & fertiliser etc $0, water $probably a few cents.  

For a total expenditure of less than $3 I got about a dozen edible sized water chestnuts.  That means each of the larger edible sized water chestnut effectively cost me about $0.24 plus produced some straw and whatever added benefit of having insects and wrens hanging around due to the water.  

Next year I already have corms to plant and the buckets so each water chestnut will essentially cost a fraction of a cent.  I doubt the buckets will last more than a few years due to the sun, but we will see what happens.

Things I plan to do differently

One factor which may have made the corms so small is that we went away towards the end of the growing season and some of the buckets dried out which meant the plants died down early.  Some buckets are still actively growing as they did not dry out as much, so time will tell on this theory.  Perhaps if they had constant water in the late season, like they did throughout the rest of the season, they would have kept growing and the corms would have increased in size.

I think that I can make the plants produce larger corms in a few ways.  Firstly I think adding more manure and having less soil will help.  More manure will mean more fertility, hopefully this fertility will help the plants to produce larger corms. 

I will probably have the soil level slightly lower and the water level slightly higher, this will help prevent drying out on hot days as happened a few times here over summer.  During summer where the daytime temperatures were in the mid 40s for weeks on end meant I would fill the water container in the morning and by the afternoon they had dried out, having lower level of soil will mean that I can have slightly more water in the bucket.  Having a deeper and wider container would help, but that is not really an option right now so I am sticking to growing in buckets.  

Growing by splitting off shoots and planting them part way through the growing season should help to reduce the number of corms in each bucket and hopefully ensure that these corms are larger.  If this does not work I know that there are some improved varieties out there which grow larger corms, but getting my hands on them seems almost impossible.

I plan to grow them again

Overall I am happy with how this turned out, I got a good yield of edible corms from a tiny space with next to no work from me, a massive yield of propagation material (and/or animal feed), and a good amount of straw.  Considering that all this resulted from planting a single corm that was only the size of my thumb nail I count it as a win.  I have a few things to change for next year to hopefully ensure some larger corms.  

They taste nothing like the water chestnuts from a can, they taste a lot nicer.  They kind of taste like something familiar that I can not quite put my finger on, perhaps coconut.  I wish they tasted more like yacon or jicama as some people have suggested that they might, but they don't.

Being a perennial vegetable it means that if I decide that I want to I can continue to grow these for ever.  Considering that the largest cost in growing these is purchasing the corms, and given how simple they were to grow, having my own supply kicking over each year seems to be a sensible option.

Where to buy water chestnut corms in Australia

Like many of the other perennial vegetables I grow I do sell water chestnuts.  The corms that I sell are larger than the ones I initially bought, but they are not as large as they will get if you give them room.  If you are interested the details can be found on my for sale page.


  1. Are they standard 10 litre buckets? I've been growing in old ceramic laundry tubs, but it's not ideal as I frequently get rain in late summer, just when the plants start dying down. Buckets would allow me to shift the plants undercover. I'm leaning towards a 20l builders bucket that Bunnings has for $7.

    Do you know if roughed up plastic would hold whitewash? Builders buckets are no more UV resistant than household ones and I'd like to find something to protect them.

    1. Hi Polly,

      They are just cheap 10 L buckets. They do not hold up to the sun all that well. The first year they are fantastic (but a bit small), the second year they are brittle and can still be moved if care is taken. That said I have some that lasted the 2 years and look like they have another year or so before they break.

      Painting the buckets sounds like a great way to make them last a lot longer. Unfortunately I do not have any experience with paint so can not give any useful advice other than encouraging you to try it and see how it goes. Let me know how it ends, I have a feeling that you may be onto something!

  2. I've had good luck using cheap acrylic house paint on lightly sanded black plastic pots, but these builders buckets say they are recycled plastic + rubber, so this is new to me too.

    My issue with using acrylic paint on pots is that when it does eventually start breaking down, I don't want the paint flakes in my garden. Everything I've read about whitewash/lime wash says it won't work on plastic, but who knows? You can't take as gospel everything you read 😉. I will try it next summer and let you know how it goes.

  3. Hi. Do you get mosquitoes breeding I'm the water? I live in Queensland and get vlots of mossies so standing water is a no no for me, but so badly want to grow the water chestnuts.

  4. I didn't have any problems with mosquiot breeding in the buckets, but have a feeling that may have been unique to that location. I have moved since then and am already seeing mosquito larvae in the water. I have heard of people having fish in the buckets to eat mosquito larvae, apparently that works well if you choose the right fish.