Sowing fall vegetables, storing summer fruits, and harvesting onions are some of the gardening activities for this month.
Keep sowing veggie seeds. Sow lettuce, beets, carrots, radishes, and other short-season crops for a late-summer harvest. Shade lettuce, if possible, during late afternoon to keep young plants cooler, or grow them next to larger plants, such as tomatoes, that provide some shade. Shading is easy using white row cover over a frame or wire hoops. Water seedlings often, and mulch between rows to preserve moisture and block weed growth.
Don't let fresh fruits and berries go to waste. Freezer jams are surprisingly easy to make, and even regular "canned" jam is pretty straightforward and makes a great gift. At the very least, freeze some berries for later use; simply spread them out on a cookie sheet and place them in the freezer; once they've frozen, pour them into freezer bags and seal. Use plastic bags specially sold for freezer use, as these prevent drying out as happens with normal resealable bags.
Begin harvesting onions when about half to three quarters of the leaves have died back. Gently dig or pull the onions and store them in a dry, shady place with good ventilation, such as an outdoor shed or barn, for 10 days to 2 weeks. Then put them in slatted crates or mesh bags and store them cool. Indoors in a cellar with low humidity and fall temperatures between 33 and 45 degrees F is ideal.
Harvest sweet corn early in the day for the best flavor. Squeeze ears to see if they're firm and wait until the silks have browned and dried to harvest. Eat immediately unless growing the supersweet varieties that will hold their sweetness for a few days. Store in the refrigerator. If you don’t grow sweet corn, or enough, buy some locally at farmer’s markets or farmstands to cut off the cob and freeze for great winter eating. Make sure and blanche first.
Blanching is simply boiling vegetables for a short period to kill enzymes that cause their deterioration. For sweet corn, place in boiling water for 4 to 6 minutes, then remove and cool. Using a knife or corn scraper, remove kernels and place on cookie sheets or trays in a freezer. Once frozen, store in resealable plastic freezer bags.
As you remove spent plants from your garden beds, if you’re not planting a fall crop, sow a cover crop such as winter rye. This will help reduce weed infestation, minimize erosion and compaction from fall rains, and will add nutrients and organic matter to the soil when it is tilled under next spring.
Roses need to start their hardening-off period by the end of August. It's hard to refrain from cutting the flowers, but allowing some to form hips will help signal the plant to begin this process. Consider harvesting some ripening hops for tea and jams.
Don't rely on nature to provide enough water for trees and shrubs that you've planted this spring or summer. Deep watering once a week will encourage deep roots which better withstand droughts and better anchor trees.