Sumac is a great plant for many uses. Smooth sumac grows around here, and people generally only pay attention to it for it's vibrant fall display or deep red leaves. The berries, if picked at the right time, can as you say, Shin, be used for "pink lemonade". I don't think it tastes like pink lemonade, myself. I didn't find the taste all too pleasing, but tolerable.
Where I live, garlic grows in abundance in the wild, so we don't plant it. We pull a years supply of it every summer, and scatter the heads of it back where we found it for next years crop. The medicinal properties of wild garlic are absolutely outstanding. I've used it to treat many ailments.
I'd like to get around to trying some different methods of gardening, like Hugelkulture. Some friends of ours have a very nice hugel bed. We till the garden in the spring, and sometimes the fall. We plant, and when the plants reach a certain height, we mulch heavily. We put cardboard down, and then put a thick layer of straw, clippings, wood shavings, or what-have-you down. This way we don't have to weed all summer and moisture is retained. July and August are almost always droughthy, so the mulch helps immensely. The cardboard breaks down by the end of the summer, and we till it all under, along with some animal poo and compost. Makes for fertile, rejuvenized beds every year.
Right now is prime time for garden harvesting. Not a day has gone by in the past few weeks that I haven't been preserving something. We've got tomatoes out our ears at the moment, and I've been making all sorts of yummy sauces, soups, and snacks out of them.
Once my company leaves this weekend, I'm going to start some fall lettuce and spinach. I don't save any of the lettuce, but I do freeze the leftover spinach for various recipes and smoothies.