Pinch Blossoms Off Melons and Squash
Pinch flowers and the tips of all the vines off melon, pumpkin, and winter squash plants to direct the plants' energy into sizing up the existing fruits. Pick off any small fruits that won't have a chance to ripen before frost.
When the tops of your onions turn yellow or brown and fall over, it's time to harvest. Some gardeners bend the tops of onions that remain green, but this can damage the necks and make the bulbs more vulnerable to rot in storage. A better idea is to use the onions whose tops remain green soon after harvest rather than storing them. Let your dug onions cure in a dark. well-ventilated spot for two to three weeks until the tops are completely dry and the outer skins are papery. Then cut the tops to 1 inch and store in a cool, dry, dark location.
Spruce Up Flower Garden Beds
Flower gardens can start to look a little ragged at this time of year, especially if the weather has been hot and dry. Deadheading or cutting back plants that have finished blooming and re-edging beds to give them a crisp, defined border will work wonders to spruce things up. This is also a good time to take advantage of late-season sales of annuals. Pop them into existing gardens to add a shot of color to beds that are no longer full of blooms.
Control Powdery Mildew
Powdery mildew can be a problem on a number of plants in both vegetable and ornamental gardens, but the disease is host-specific. The powdery mildew on your phlox won't infect your squash plants. This fungus disease thrives when conditions are warm and humid but leaf surfaces are dry and shaded, which is why crowded plants with poor air circulation are most susceptible. Avoid overhead watering to keep humidity levels low. The biological fungicide Serenade can be used as a preventative spray. Neem oil or horticultural oil can help reduce existing powdery mildew infections. Be sure to read and follow all label instructions and precautions when using any pesticide. Clean up and destroy infected plant material at the end of the season; don't compost it.
Sow Seeds for Fall Salads
Sow seeds of spinach, lettuce, radishes, kale, bok choy, and Oriental greens like mizuna and tatsoi for delicious home-grown salads come fall. If you sow seeds in a cold frame or in a bed that you can cover with row cover fabric, you might even be able to serve greens from your garden for Thanksgiving dinner!