Flexi tub pond for vegetables

For over ten years I have been growing water chestnuts in a bucket.  It is simple, it is cheap, and it works well enough.  For the past seven or so years I also grew some duck potatoes and Chinese water chestnuts in a large flexitub with some soil in it.  

From this I got much the same result as I get from growing them in a bucket, but a yield of larger corms.  Strangely, I seemed to get a similar number of corms, but the flexi tub seemed to grow a lot more larger ones that were of edible size.  

Unlimited water, unlimited air, no weeds, aquatic veggies grow fast

As with the buckets, these tubs eventually degrade and fall apart from the sun.  Below are photos of a flexitub that I have been using as a pond, it has been there about seven years.  

The photos below were taken at the beginning of spring when the duck potatoes were starting to break dormancy.  You can see in the photo above that the duck potatoes get a lot taller than this and largely shade the water.  

Duck potatoes in flexitub

Being in a larger pond meant there was more room for soil, and the temperature doesn't fluctuate as much as the buckets.  I allowed azolla and duckweed to grow in there, eventually they cover the surface of the water and start to mulch down.  

Small birds come to drink from my flexitub, and dragonflies and water beetles seem to breed in there.  Over summer when the surface is covered in azolla, honey bees come and drink from my pond. 

The birds seem to prefer the larger tubs to the buckets, I like being able to provide some water for them over summer.  

Leaf litter breaks down to fertilise the plants

You may also notice that these larger tubs catch a fair bit of leaf litter and lots of flower petals, all of this breaks down to fertilise the plants. As the plants get taller they almost act as a net, catching leaves from the air, and depositing them in my tiny pond.  

The photos below were taken towards the end of spring.  You will notice a lot of growth happened over this time.  These plants have the best of all worlds.  They have unlimited access to fresh water, unlimited access to air, plenty of direct sunlight, lots of nutrients in the mud, never any weeds, and a healthy little ecosystem which captures and cycles nutrients.  

It doesn't take them long to grow large

Over winter I will add leaf litter from when I clear out the house gutters, and this combined with whatever else that lands in the water provides all the fertiliser needed for the growing season.

When it is windy the leaves capture anything that is blowing around and directs it into the tub.  This breaks down and feeds the plants.  Various insects such as dragon flies and water beetles breed in the water.  These insects eventually die in the water, and their little bodies eventually break down and feed the plants.  

Some insects that breed in there would fly away, taking nutrients with them, but this little tub seems to accumulate nutrients overall.  

Sadly these flexi tubs don't last forever.  You can see the one above is starting to degrade, it may only have another year or two left in it.  

I have had it in full sun, getting hit by wind, hail, heavy frost, and storms for over seven years.  While I would prefer it lasted a lot longer, seven or so years isn't too bad. 

These flexi tubs are great little ponds for emergent aquatic vegetables such as Chinese water chestnuts, duck potatoes, water celery, brahmi, and water cress.  If you were growing something like Lotus or Water Lillies they may do ok, but may benefit from a larger tub.  

Chinese water chestnuts 

Duck potatoes 

I have a for sale page where I sell water chestnuts and duck potatoes and other perennial vegetables in Australia.  I update the page regularly, and it has my email address that you can use to contact me.