If you can't do anything else, deadhead. When weeds start to flower, chop their stems before the flowers can turn to seeds. That won't kill this year's weeds, but at least next year's weeds won't be worse. Cutting back flowering weeds before they make seed will really help bring them under control.
How do you deal with a stand of wild mustard or huge clumps of goldenrod? Power tools! Weed whacker to the rescue. As a gardening tool, the weed whacker lacks finesse, but you can chop the tops off a whole lot of weeds, very quickly. As a bonus, some of them – especially tree seedlings – may be discouraged enough to turn up their toes and disappear.
What if you look out and see telltale white fluffs or crunchy brown spikes ? It's not too late to prevent a new crop of weeds! Arm yourself with pruning shears and grocery bags, and go after those bad boys. Carefully bend the seed heads down into the bag, then cut them off with the sheers. You might use similar methods when you shake down free seed from your garden flowers, but in this case your harvest is headed straight for the trash! I suppose if you have good compost "cooking," with temperatures getting nice and hot inside the pile, you could try composting your weed seed trash. Tossing it seems more prudent.
Once seeds have dropped, you're still not doomed to being overrun with new weeds. Germination inhibitors are your secret weapon in the War on Weeds. Also known as pre-emergent herbicides, they stop weed seeds from sprouting in your yard and garden. "PreenTM" is the best-known brand for garden applications, and "HaltzTM" is most often found in lawn fertilizers marketed for spring application. Corn gluten is an inexpensive organic alternative for preventing weedlings in both lawn and garden.
One drawback to using pre-emergent herbicides: it stops all seeds from sprouting, not just weed seeds. Their use means you can't plan to top-seed or reseed any bare spots in your lawn this year. Stopping seeds from sprouting also means you won't benefit from self-sowing action of "good" plants that scatter their seed generously. Reseeding annuals from Ageratum to Zinnias can add a lot of color to a border. And it's fun to find "volunteer" columbines, salvias, hibiscus, etc. popping up around the parent plants. On the other hand, you may not miss the tangled jungle of morning glories trying to take over the bed where you let "just one" plant go to seed.
Stop weed seeds from forming, stop them from dropping, stop them from sprouting. If you do at least this much, your garden may not be weed free next year, but at least you'll be preventing a huge increase in their numbers. It's the first step in the War on Weeds!
Photos by Jill M Nicolaus. Mouse over images for additional information -- just hover your cursor over the picture, and a popup caption will appear.