DIY self-watering!

I have a 6 inch depth 3x3ft tray (no holes) that I am wanting to make use off.
I’m wanting to put it on a trellis table on my south facing patio to grow salad.

My thoughts are making a DIY self-watering system made up of 2 oven shelves placed over the water in the tray on some type of stilts (thinking of wooden blocks) then covering the oven trays with capillary matting with one side of the mat falling into the water.

If this works my Gem Lettice / spring onions and shallots should never get wet bottoms
in their own planters.

I know I will be needing some sort of shade IF the sun gets really strong, which can be sorted with a covering of light fleece- after making a cloche out of old hosepipe LOL

“last year was my first ever grow of tomatoes and now its first time for salad“

Comments/feedback will be appreciated

 

Are you relying upon the crop roots growing out through their pot/tray bottoms on to the matting? I think you will need to create some kind of wicking into these trays/pots to establish the plants or solarpump the water onto the compost surface from the tray, to then recapture the drained back excess.

 

I tend to think the oven trays would need a plastic sheet under the capillary matting in order to get good contact between the matting and the pot holes.
The roots will actually start to grow into the matting after a while but that is all to the good for the plants.

Thinking about it a flat surfaced shelf rather than a oven wire type shelf might even work better.

 

You are describing a popular Wick watering system, so it should work ok.

Though from what we have read, you initially need to water from above until the roots get down into the compost.

eg -

 

I've used capillary matting in the past and there is a specific amount of lift you can get from it, a few inches at least.
As long as there is good contact between the compost in the pot and the matting it works ok, so none of those silly crocks in the bottom of the pots.

 

I hoped for good advice and I have certainly got it
At the moment i'm looking at Capillary Matting from
Search results for: 'capillary' | WM James & Co.
It is the right size and not expensive.

@infradig -As I will be growing salad, I'm thinking I will be replanting every 4-6 weeks to keep up with my family eating them all. If I drill extra holes in the containers there will be more chance of the water in the matting been drawn upwards -depth of the troughs are 18cm " am I right or wrong

@Drahcir - Lol, the tray has been propped up against the side of the house for a few yrs.. we used it for a dogs padding pool

@pete - "YES" that could work a lot better and we have some old damp course plastic in the shed I could used.
As we are short of space its the only thing I can think of that will work best for me with the table being waist height, and out of reach of our dogs.

 

Thank you @ricky101 - Nice to see in all in print, and yes I will water around the inside rims until they are nice and sturdy. I only hope I will be showing off with pride and joy of a plate full of my growing produce in the months ahead

 

Just watch out for greenfly etc on the lettuce, a regular problem.

Got some Little Gem lettuce germinating as we speak along with some Salad Bowl pick and come again loose leaf ones, have you tried them ? always quick and easy to grow.

Would think some Beetroot and Raddish would do well in your tray.

 

It will probably be too hot for lettuce if it's south facing. Even where I live, I keep them in a shadier spot as they bolt very easily.

 

I have been using capillary watering for over 5 years now and find it to be an excellent system for bottom watering. The seedlings that are down in the cellar, under lights, feed from a receptacle of water which I replenish every morning. It only holds about a gallon but I don't mind as I'm never away very long or my sons will pop in and top up.

I use this system out in the greenhouses too. I'll see if I can find a pic....

This was before I started putting the seedlings out there - the snow is the give away that it was early last spring. The grids are raised off the floor with wooden L's and T's and the receptacles sit just under the grids. Then there are tongues of felt which are dipped into the troughs to draw the water. The troughs are filled by a watering system or it can be done manually.

And it does seem to work well. I sometimes add water soluble fertilizer to the troughs and also keep a bit of "mosquito bits" in them to stop any gnats or mosquitos making them a breeding ground. The water in turn kills soil gnats in the pots. This is about three weeks after moving the large seedlings out there.

 

Any felt will do, I get mine from a discount fabric place.

 

I agree with most of the comments above.
Lettuce can be harvested by using leaves from the outside first, which enables cropping over 6-8 weeks. A 'flying start' can be had by buying a supermarket 'living salad' , which is a bunch of lettuce mixture grown and sold as a clump*. These can be pricked out into pots as an early start to the season, while your home raised plants mature. It would also give you a chance to fine tune your system.
*Got more than 70 lettuce plants from a single 'salad' on one occasion, for 99p. They tend to be oakleaf types, in various colours.

 

A janitors string mop would be a suitable cheap source:#
www.screwfix.com/p/stronghold-healthcare-kentucky-mop-heads-white/844kh