Timely Tips

What to Do in July 2025
Weekly Gardening Timely Tips from
Cornell Cooperative Extension of Westchester County

July 13- July 19

Perennials: Is the garden humming with pollinators? Enjoy the show! To attract pollinators and other beneficial insects, employ groups or swaths of flowers with a diversity of shapes and bloom times. These include mint family plants such as mountain mint and sage; coneflowers, daisies and sunflowers in the composite family; dill, fennel and parsley in the carrot family (Apiaceae) and many more.

Flowers: Check flowering vine supports. Vines can become heavy this time of year, and in need of extra stability. Tie plants directly onto stakes always use a loose knot to prevent girdling.

Fruits and Vegetables: Begin to monitor squash for vine borer. While you’re in the garden, check other vegetables for insect and disease pests. Spotted lanternfly nymphs may be found on cucumber, squash and other vegetables. These may be in the black and white phase or with added red coloration. Grape vines are a preferred host of this invasive pest, and can kill the vines when feeding pressure is heavy. See Spotted Lanternfly | CALS (cornell.edu) for more information.Once apples have reached full size but have not yet begun to color, monitor for apple maggot by hanging one red sphere trap with a sticky coating per each 100 fruit. This may catch enough of the adult insects to reduce damage to a tolerable level if you have only a few trees. Keep the traps clean for best results. Contact your local Cooperative Extension for advice.

Trees and Shrubs: If you planted trees and shrubs this year, remember to continue watering them regularly. Apply an inch of water weekly, inclusive of rainfall. New installations need consistent watering to become established over their first 3 seasons. Plants that have matured in the landscape also benefit from supplemental water in hot dry weather. Be careful as poor drainage could be a recipe for failure and as bad as drought for many trees and shrub species, as can overwatering.

Lawns: Grass growth slows down considerably or stops in hot weather. This month and next, the lawn won’t effectively take up fertilizer. Wait until the weather begins to cool and steady rain returns in early fall to fertilize if needed, usually around Labor Day. A well-established lawn may be recycling enough nutrients that additional fertilizer may not be necessary.

Houseplants:After a flush of growth, prune or pinch back houseplants to keep them looking full. Keep an eye out for aphids, mealybugs, mites, scale insects and other pests. If you find them, contact your local Cooperative Extension for advice.

Last updated July 14, 2025