I don't think square foot gardens and containers really have much in common. But one thing they do have in common is that they need good drainage, and you're not going to get that with a mix of topsoil and compost. The mix is "sinking" because all the air is being squashed out of it and the compost is shrinking.

The standard mix for a SFG is one third each compost, peat and vermiculite. If you chose not to use that because you prefer to go "organic," you might want to pose your question in the organic gardening forum. There you can learn about what to add to your soil to loosen it up and feed your plants.

It actually seems to be draining very well, from what I can tell. It definitely drains out the bottom and doesn't seem overly saturated when I check it mid day. Nor does it seem very compacted when I dig, but very loose and soft. I actually did one box with the vermiculite, peat and compost mix, and those plants are doing the exact same as the rest--I guess I should have included that info in the original post! I guess different people have different opinions about SFG. I'll just have to keep trying to figure this out.

~hollieberries,
I tried SFG years ago with great success. I look at it as a concept in space saving.
If the container is closed, as in has a bottom to it, then in a way it is similar to container gardening.

If not, it's basically a raised bed.

Does yours have a bottom to it? or is it a raised container?

Alot of the plants you listed, especially the tomato's will slow down in growth with the heat. When the temps are consistent over 90*.

If there is yellow leaves, it could be a problem with your soil or fertilizer.

If it's a closed box, then top soil and compost is not going to drain properly, as ohiofem points out, it will compact over time.

5" of soil doesn't sound like much for the types of plants that you have . My boxes were 8" and it didn't sink.

What is the size of the box? How much did the soil compact?

I personally have never had much luck with vermiculite, in any containers or SFG.

My SFG were about 60% compost, 30% a bagged mix for containers, and 10% Perlite. I'm not saying that's the right way to do it, or amounts, but that is what worked well for me, and my box had no bottom to it, so the earth acted as a wick.

I ventured into SFG as something new to try due to a very small yard. But when we got a big dog, we needed the space, and I moved all the garden to the front yard in beds and pots. Now we have 3 small monsters, and a pool, so it's still in the front. lol...

I hope you can figure out some of what's going on.

What is the tomato in the pot planted it? What type of soil?

JoJo

Okay, well the bottom is open--just newspaper underneath, so I guess then it's not the same as container.

As far as heat, we had a huge heat wave this past week and that is when the vine tomatoes actually started to grow more. It's also when I started to back off on watering as much.

The boxes are 4x4 and 8 inches high. I think the soil compacted maybe an inch.

The pot tomato is just in a large plastic-type dark red pot. Soil and compost mix.

I hope I can figure it out too. Thanks!

hollie, what is your zone?

Oh, sorry! Some people say 8a and some say 7b. It's right on the very southeast tip of VA. So take your pick :-)

Could be two things.

1. compost soil mix was too strong burning plants.

2. the compost was too light or did not contain enough macro nutrients like K or Ca to produce fruite.

I guess those things are possible. The only thing is that my friend and I are both using the same exact mix (we bought it and just split it between us) and her plants seem to be growing quite well. She has been adding rabbit poop to hers though, so maybe that is the difference.

If you look at the difference yea that could be it.

It's very likely that your plants are deficient in one or more nutrients - especially if the 'compost' wasn't finished. I'm not sure how you want to go about adding nutrients from an organic source that would be immediately available in a reasonable ratio - I'd leave that decision up to you. I'd simply add a slow release fertilizer in something close to a 3:1:2 ratio or use Miracle-Gro in 24-8-16 %s on a regular basis until you get your soil healthy.

I had to fertilize the heck out of my RBs the first year they were established to get things to grow because of the N immobilization.

Al

Well, it does appear that the vine tomatoes are growing better, and I think the cukes and basil too. But the parsley, thyme, rosemary, peppers, and the bush tomato--not so much. Actually the bush tomato is looking pretty sad. I am getting some rabbit compost today so we shall see what happens.

It could be bad drainage.