Topic: You may be looking for more cropping space at home during self-isolation BUT...

[Vinlander]

Don't fill your pond - you can turn it into a slug-proof zone for growing salads without even draining it (or bothering your fish).

I have used this pontoon garden method and it works well (like the Aztec lake gardens - chinampas) - slugs can't swim (though you have to be sure none get in with the plants). After a quarantine period with no chewing you can rest easy - otherwise you might need to use some traps.

However you should take the opportunity to lift your waterlily out first and divide it into cuttings in buckets.

Once you've done that you can be sure nothing is going to crawl in - because the strings that hold the rafts in place can run under the water from the bottom of the raft to wire loops under the water round the edge (the other end of the stiff wire comes out of the water and is held under the stone edging).

You need capillary matting to get the water out of the pond & up onto the floating pontoon.

The simplest system is to tie empty plastic bottles together to make a raft and put a stiff light cover on top to hold the growing medium. Old twinwall PC roofing is excellent, the twinwall stuff used by estate agent signs is fine as long as the floats under the raft are well connected so the raft has its own rigidity - much easier using square section bottles but not impossible with round ones. For salad crops the raft needs to be at least 3 or 4 times wider than the height of the growing medium (or pots) or it will capsize. Bulkier crops will need wider rafts. Growing corn and beans was no problem for the Aztecs because their rafts were 30 feet wide

If you cover the raft with capillary matting you can put your crops in pots on top - this is more expensive but simpler and easier to manage and clean.

If you use the minimum of matting around the raft edges and the growing medium in the middle area then the medium only needs to overlap the edges of the matting more than say 7cm to transfer the water. It only needs to be maybe twice as deep as a seed tray so the whole thing is lighter.

If you can't sink the raft by over-watering the medium/pots on top you don't need to worry about rain - the capillary system actually speeds up drainage.

One thing - Don't use expanded polystyrene - it is porous enough to sink a few cm a day even with nothing on top. Wrapping it in plastic is no good - unless you weld every seal the rain will get in and sink it. Closed cell stuff is possibly OK but bottles are safer and easier to clean at the end of the season.

A bit of work - but what else are you going to do while you are trapped inside? Watch daytime TV? No chance...

Cheers.

PS. Needless to say, you need to make sure the bottles round the edge cannot slide in or out so you will also need strings running from side to side over the cover.  You could wrap the whole raft in plastic before putting the mat on (though this is no good if there are spaces between the bottles - loose bottles can cause a capsize so every one would need tying in place first).

[ancellsfarmer]

Brilliant!
Lack the space to create the pond . May requisition the front lawn from Mrs AF, but for raised beds.

[galina]

Does anybody remember the photo of how much one terraced house in UK could grow?  I cannot find it anymore online.  But all the windows had window boxes and the small garden had a lot of vertical structures with horizontal half drain pipes slightly slanting so that one pipe drips into the one below.  Those were filled with strawberries, salading and small veg.  Even longer ago there was the series, all muck and magic on Channel 4 where a tiny suburban garden provided all fruit and veg for a family.  A repeat about now would be useful. 
https://www.rhs.org.uk/advice/grow-your-own/containers/veg-on-walls
Any vertical gardening and also square foot gardening videos could give lots of ideas for intensive small garden growing.  And we have our own guru on hand who recently converted from several allotments to a much smaller garden.  TeeGee has put out much information that will come in handy for many of us this year. 

[ancellsfarmer]

Unfortunately, we are addressing the enlightened. Now is the time for society to get real and sort its priorities. Perhaps farmers will become appreciated, maybe growers will not be looked down upon as peasants.
 It will be interesting to see whether, for instance, local councils give up more of their land for allotments. Perhaps they will permit polytunnels to be used without planning permission. Unlikely to be an issue this year but we might hope for adequate water supplies for irrigation of food in a hot summer
Somewhere in the recent past, humans have lost sight of reality. The declared inability to cook, from basic ingredients, grow any food,raise or  prepare meat or fish, let alone respect those who can, is a shortcoming many may live to regret.

[DrJohnH]

Genius idea.  Love it!  Now I need to build a pond...