Onions are ready to harvest when their tops begin to die back and bend over. Dig the onions when the tops are dry and brown. If the tops of some don't bend over on their own, harvest and use these first, as they won't store well. Then cure onions in a warm, dry, well-ventilated spot out of direct sun for one to two weeks until the tops are completely dry and the outer skins are papery. Cut the tops back to 1-2 inches (unless you plan to braid them) and store in a cool, dry, dark place.
Give Re-blooming Perennials a Midsummer Feeding
When you cut back perennial flowering plants that often have a second, smaller flush of bloom later in the summer, like catmint, threadleaf coreopsis, yarrow, delphinium, and globe thistle, give them a light feeding. Mix a small amount of granular organic fertilizer with compost and spread it around the plants after pruning, scratching it lightly into the soil.
Check Spruce Trees for Galls
Check your spruce trees for the pineapple-shaped galls formed by spruce gall adelgids (also sometimes called spruce gall aphids). Feeding by these pests causes distorted growth, yellowing needles, and weak growth that can break in storms. Norway spruce is especially susceptible, but white, black, and red spruce may also be infested. Look for the 1/2 to 1 inch long, greenish-purple galls at the base of the new growth. Prune out and destroy them now, before they open and turn brown later in the summer and the adelgids feeding inside emerge to lay eggs.
Keep Up with Watering
Make sure plants have adequate water, especially when we have a hot spell with little rain, conditions common recently in much of New England. If there has been less than an inch of natural rainfall in a week, consider providing supplemental irrigation, especially to newly planted trees, shrubs, and perennials. Even drought-tolerant ones that have been in the ground for only two or three seasons may not yet have developed the deep root systems that help them weather dry spells. When you do irrigate, water plants deeply, enough to soak the depth of the root system. Watering early in the morning reduces water loss due to evaporation and allows leaves to dry quickly, minimizing the disease problems that wet foliage promotes.
Maintain Container Plantings
Container plantings dry out quickly in midsummer heat. Some may need watering more than once a day in the hottest weather. Keep plantings vigorous with regular feedings of a half-strength soluble fertilizer, such as fish emulsion. Make sure the soil is moist before you feed; don't put fertilizer on dry plants. Trim back plants like petunias that may have grown straggly, to promote a new flush of bloom.