I have just got back from a 2-week holiday in late June. I don’t normally go away in June, and when I left, it had barely rained for a month, so I was worried sbout my still small plants surving. To try and counter this, I set up a version of the irrigation system I usually use in the greenhouse outdoors. I had already made the decision that I wasn't going to try and keep anything alive in the greenhouse this year because of that holiday, so I didn't need it for that.
What I did was fill large plastic containers of the sort you can buy at your local DIY store with water. I then dipped self-watering wick cords into the water to get the whole cord wet. I arranged these cords to run from the bottoms of my containers to the soil near each of my plants and tucked the ends of the cords into the soil.
I did this a couple of days before my holiday so that I could see if the water was coming out at an appropriate rate. In one case, it seemed to be running too fast, so I tied a knot in the cord to slow it down.
Luckily for me, it rained quite a lot while we were away, because some of the containers came very close to running out of water. I'm not sure how much the rain replenished them. Anyhow, I came back to this:
What didn't survive was my kale, although I can’t rule out this having been eaten in its entirety by slugs rather than having bern insufficiently watered.
At any rate, the irrigation system seems to have been worth setting up. It's more unpredictable than setting it up in a greenhouse, and I wouldn't want to have to bet on it working under all conditions, but it does seem to be worth a shot.
