Timely Tips

What to Do July 2024
Weekly Gardening Timely Tips from
Cornell Cooperative Extension of Westchester County

July 22- July 28

Perennials and Flowers: Resist the urge to move most perennials now (sedum may be one exception). Spring blooming perennials that are crowded and losing vigor are best divided in late summer or early fall. Division renews the plants and helps to maintain vibrant flowers and reduce the risk of disease. If you must move plants, mulch to moderate the soil temperature, and pay special attention to watering and weeding. Annual flowers that love the heat are in stride. Keep the spent blossoms of most annuals and perennials picked to encourage additional flowering. Leave those that are grown for interesting seed heads or if you plan to save seed. Consider ordering bulbs now, rather than in the fall, so you’re not shut out of popular choices.

Fruits and Vegetables: Start seed of broccoli, cabbage and cauliflower indoors or in a protected area outside. Next month, you can transplant these seedlings into the vegetable garden for a fall harvest. Last call to plant fast-maturing green beans, summer squash, sweet corn directly in the garden for a fall harvest. Harvest ripe peaches, plums, and raspberries.

Trees and Shrubs: Most trees and shrubs require little if any fertilizer. Applying fertilizer in the heat may cause injury. So it’s best to avoid fertilizing trees at any point unless there is a demonstrated need, determined by a nutrient test. Powdery mildew may become quite obvious at this time of year, especially on lilacs. This may be unsightly, but isn’t significant to the health of the lilac, so treatment isn’t necessary. Some other plants (such as ninebark) may be more severely infected. Contact your local Cooperative Extension for advice. Spotted lanternfly nymphs and early adults may be found now. These prefer tree-of-heaven (Ailanthus), and may also be found on many trees, grape vines, and other woody plants. See Spotted Lanternfly | CALS (cornell.edu) for more information.

Lawns: Cool season grasses slow or stop growing in hot weather. So far this year Westchester County has had plenty of rain, but it is still possible that the lawn may brown and go dormant if we enter a dry spell with high summer heat. Fertilizing the lawn won’t do any good during the height of summer and may be harmful, when the plants are stressed by the heat. Wait until early fall.

Houseplants: Container plants outside may dry out quickly in the heat. Check plants and provide moisture if needed. Many houseplant leaves will bleach in strong sunlight even with some shade. Move affected plants into a more heavily shaded area if needed.

Last updated July 23, 2024