I agree, nothing that is typically called a tree is suitable for that size. There's any number of suitable plants, I might recommend a strawberry bush (euonymus anericanus) or an oakleaf hydrangea (hydrangea quercifolia) as suitable Arkansas understory natives. Strawberry bush is a lank green stemmed shrub with long arching branches and attractive autumn fruits . Common witch hazel is a much denser plant with weirdly attractive flowers just after leaf fall in the autumn.

My summer squash (Black Beauty zucchini, Italian Striped zucchini and Yellow Straightneck squash) didn't thrive in the shade. The Yellow Straightneck squash should have had enough sun, though, but I guess either it wasn't enough, it was just too hot, or there's something wrong with the soil (too much rockdust and potassium, maybe). I'm still waiting for fruit. However, they might just need more phosphorus or something. The most shade-tolerant tomatoes I have seem to be Black Plum and Galapagos Island (Solanum cheesmanii). Georgescu Chocolate peppers produced a few peppers in the shade. I'm planning to grow more heat-tolerant crops next year. Even the plants in the shade were super hot, this year. As for cucumbers, neither the ones in the shade, nor the ones in the sun prospered. However, the ones that did the best of those surprised me. Those were ones I didn't thin (I just let a whole bunch of them grow together in one spot, and they actually bore fruit, while the ones by themselves didn't; they were larger, and grew faster, than the ones by themselves, too). I thought this was particularly interesting, because it goes against what people usually tell you to do (and against my experience with some kinds of plants—you know, when you have two tomatoes growing in the same spot, it usually diminishes the results). Whatever the cause, I want to try not thinning them next year, too. I've very curious to hear if anyone else has tried it. I'm planning to grow parthenocarpic and heat-tolerant cucumbers next year, though: Monika, Little Leaf and Beit Alpha. That should change things a lot. This year, I grew Jolly Green and what I believe is called Bushy. They definitely weren't heat-tolerant, but Jolly Green did much better than Bushy in our yard, this year (or at least it's done better so far). Parthenocarpic squash/cucumbers should do better in the shade. Part of the problem with shaded plants is that insects (which could pollinate) tend to stay in the sunny areas more. So, if you don't need pollination to set fruit, you should have a big advantage in the shade. I don't have any parthenocarpic squash, at this time, but I do have seeds for a heat-tolerant zucchini for next year (Dark Star). I'd really like some parthenocarpic ones, though (particularly if they breed true).

yes yes yes! the hydroponic guides i've read are not nearly as geared towards the novice as this one. and it's also really excellent in regards to small setups which is where i'm coming from. it's '81 but dammit everything is still relevant even the terminology enough i can walk into the hardware store with a list and there is no problem. it is beautifully written, great instructions, doesn't make you feel like there are things you can't do but is realistic. amazing. pictures. of course it's not an anthology, you must have further information on proper care. but it is most definitely a welcoming approach to hydroculture. talks about using cut-in-half empty gallon milk jugs with a tube connected via fitting in a whole on the side near the bottom that runs into a quart-sized glass jar beneath. jar holds the nutrient solution which gets poured into the milk jug then drains back into the jar relocated below. medium is simply some pea gravel. one vegetable plant per jug. perfect for a shelf-lined windowsill i have. he talks only about growing under 4ft. fluoro shoplights. i'll let you know how an experiment with cfl's goes. peace, brothers.

Looks like pilea pumila. Pull them out now and don't let them go to seed. It will take a few years to get them all but it's worth being vigilant. Easier to pull when small because the roots hold a lot of soil.