Self watering containers

[hathor]

Hi all

Having just read a book from the library (American, unfortunately) all about growing veg in self-watering containers, it would appear that some plants, such as tomatoes & peppers do better in the constant growing conditions offered by the above than they would in the stop/go moisture of a periodically-watered pot. (My situation does not lend itself to automatic watering systems, so it would be just me and a can: in between splashes, the pot progressively dries till the next dose of water seems to be the gist of the book, which tomatoes etc do not appreciate. In a SWC, they have optimum moisture all the time, provided the reservoir is kept topped-up.)

So then I started looking at SWCs and have been a bit put off by the price, so I thought I'd try the Blue Peter route & have a go at making my own. (If successful, my patent design will be on here for all to copy, natch! - not that I'm claiming any great expertise, I hasten to add.)

Anyway, to my question: do the experts think that it is important to ensure an air gap between the water in the reservoir at the bottom of the container and the potting medium (as in the Earth Box design) or would the plant roots be sufficiently aerated by the use of a compost/peat/vermiculite blend which does not compact like soil? The self-watering hanging baskets I have seen don't seem to have any such gap, so far as I can tell.

Comments/advice, please.

[Alison]

I'd have thought that the gap is pretty essential to stop the bottom of the plants getting water logged. I have some self watering hanging baskets (very cheap several years ago from Wilkos) and they have a water reservoir at the bottom with a plastic tray over it. There is then a capilliary mat covering the top of the plastic tray with a wick dipping into the water. Therefore if the soil is dry, the wick pulls more into the mat etc therefore damping the soil and watering the plant. Dead simple and VERY effective.

[hathor]

Thanks for that.

The Earth box system has the soil itself acting as a wick, by filling two corners of the box right from the very bottom, while the rest of the soil stands on a perforated board above the maximum water level, with an air gap between the water and the board.

I was thinking of standing a false bottom on little legs in the box, with capillary matting as the wick, with the ends in the water, and the soil standing on the capillary matting. This would ensure the efficient moistening of the soil, but I think the capillary matting would block up any air holes/perforations I put in the false bottom – can’t see air getting through wet capillary matting – so there wouldn’t be any aeration of the soil, so no need for an air gap above the water, if you see what I mean.

The soil wouldn’t stand in the water itself, but would be constantly replenished with water from the matting, assuming I keep the reservoir topped up. I’m just not convinced that making sure the false bottom is clear of the water serves any useful purpose if the holes are going to be blocked up by the matting.

[Demeter]

This all sounds very complicated.

I've followed the suggestion of many on here who say get a bucket and drill holes an inch or two from the bottom so that the bottom acts as a reservoir. The effect is that the bottom inch or so is presumably going to be very waterlogged. This is my first year so I'm not going off my own experience, probably I am missing something - but if the "drill holes in the side of a bucket" method works, why all the science for the "patented self-watering pot device" method?

Edit: I've just remembered I have a couple of "self-watering" containers. As far as I can remember, all they are is containers with a plastic tray in the bottom on little legs to make a reservoir, with perforated "wells" so that the soil in the well comes into contact with the water. I think. Can't check cos they're full of salad & herbs right now!

[wistow-wizard]

I have tomatoes in a tub with a water reservoir, plate with holes in above the water and compost above that.
I purchased 3 varieties of plugs, grew on in conservatory and planted out in early May
They are 5ft high with two trusses set.
Going like the clappers, much better than standard tubs from last year.

[hathor]

Thanks to all you folks for your valuable input.

Wistow wizard: your experience seems to validate the claim of the book I started with, that SWCS are better than conventionally-watered ones, which is good to know.

I always like to try and query any book’s claims if poss. While I would not accuse any author of being untruthful, by definition they have a major axe to grind if their principal claim is the whole thrust of the book, so they may be tempted to be less than objective, or downplay any disadvantages.

Between you, you have also confirmed that you don’t have to spend heavily to get results, which is also good.

As an erstwhile non-gardener, I really appreciate the advice available in this forum, particularly as I am not made to feel foolish by posting what to many must seem obvious questions. Thanks again.

[Claire72]

I bought a self watering container from Aldi for my fuschia bush a while ago and it seems to be doing well with it, but not sure of the ins and outs of it.
Don't seem to remember it being expensive