Watering from below doesn't allow for excess salts, from fertilizer, to be flushed from the soil, so you'll end up creating problems down the road. It works good when you forget to water and the soil becomes hydrophobic, but I wouldn't recommend doing it all the time.

Joe

And then there are those of us who use sub-irrigation consistently with great results. I know it sounds a little snarky, but sometimes I think that those who downplay that method are too smart by half. I am in my second year of using that method, and am trying the rain gutter system where water is constantly available, and my plants in that system are doing great with no problems. I'm sold, and will be converting most of my raised beds to sub-irrigation next year. The only ones I won't convert are the strawberries because I don't want to uproot them. Here's a photo of my rain gutter system.

Semi-hydro and hydro set-ups are a bit different than "watering from the bottom" in traditional containers.

Josh

I don't grow annual plants in containers, only ones I keep year after year. So, I suppose in the course of a growing season, you may not have issues, but over the course of several, you will. So for annuals, go nuts I guess, but for anything you intend to have more than a growing season, I wouldn't do it....but then again, I'm only smart by half.

Joe

From the picture of the 'rain gutter system' it looks like the containers are actually clear of the water. If this is true, is there a wick from the bottom of the pots into the water? How far into the season can you go before the roots grow into the drainage holes, perhaps even plugging them up? Al

Joe, I owe you an apology. I should have been nicer on my post, and you didn't deserve my "snarky" attitude. Please forgive. I'm not an expert by any means, I just know what grows well in my garden, and you are right, it's mainly veggies and they get replaced every year, and the soil gets amended too. I haven't got much that is perennial, except for one Japanese Maple, and it's new this year. I am having a lot of success with sub-irrigation though, so much so that next year I plan to expand. Again, sorry for the bad attitude.

nattydoll, that's almost a sacreligious question on this forum :-) ...only kidding. That means your containor soil is fine enough to wick water up from the bottom instead of draining it from the top down out through the bottom, which is what a lot of us shoot for.

Now for sub-irrigated containers that's totally appropriate, which is what it basically sounds like you have, although not in the traditional sense. I've used them in the past, but not this year. If it works for you great! Maybe you could share what soil mix you are using. I'm guessing maybe a standard bagged potting mix.

I watered my citrus seedlings from the bottom for the first three months but watered from the top after that.

The rain gutter system I have uses net cups poking out of the bottom of the buckets and they sit in the water. The net cups are filled with potting mix, as is the rest of the bucket, and the water wicks up through the net cup. Last year I had tomatoes in a couple of Grow Boxes, and the roots grew down into the water reservoir, but the plants didn't seem to mind. I like this method better because the water is controlled by a float valve and I don't have to water it at all. I'm out of town sometimes visiting family.

Gjshawk, apology accepted, no harm done. Anyhow, I guess I cannot argue against this rain gutter system, as it appears to be working for people. I think though that the original poster was referring to just regular old pots, dipping them in water, and allowing capillary action to do the watering, rather than a gutter type system. But, as noted, I don't grow annual veggies in pots, as I am blessed with plenty of space, with good soil, which I've built up over the years with compost and such. My container growing consists of quite a few jades and some tropicals, plants that don't take well to excess salts or excess moisture. I've thought of doing some indoor hydroponic veggies though, but that's a topic for another time.

Joe

Thank you gishawk, for the further explanation of your rain gutter system. Al

If you used a live mix instead of a dead mix, you could use organics, and if with rainwater, salt built-up would be non existent.