Timely Tips

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

March 23 to 29

Perennials: You may be itching to get into the perennial beds and start cleaning them up. Don’t rush the season!If the soil is still soggy, wait until drier condition prevail. (If it’s dry enough to crumble in your hand when you form a ball, it’s ready.) To avoid soil compaction from foot traffic in garden beds, create paths for access and stay on them. Once the weather begins to settle, cut back browned foliage of bishop’s hat (Epimedium spp.) and other ground covers, taking care not to damage fragile new stems. Remove the old tops of ornamental grasses before new growth appears. Leave at least 6 to 12 inches of hollow stems for cavity nesting bees, and the new growth will hide them.

Flowers: Weather permitting, you may start planting pansies in moist but not soggy garden beds or outdoor pots now. While you’re outside, check for spotted lanternfly (SLF) egg masses which may be present on many landscape surfaces. SLF is a major agricultural threat that can kill crops (grapes, fruit trees and others) and affect landscape plants. Seehttps://nysipm.cornell.edu/environment/invasive-species-exotic-pests/spotted-lanternfly/.Crush as many eggs as you can find. Use a card to scrape them off of surfaces into a sealable bag, squish, and discard in trash.

Fruits and Vegetables: Start seeds of slow-growing vegetables such as eggplant and peppers indoors. Begin to acclimate hardy cool season vegetables to outdoor conditions so they are ready to plant when the garden soil is workable. Prune apple and pear trees when they have thawed out but have not yet bloomed. Wait until after bloom to prune cherries, peaches, and plums.

Trees and Shrubs: If oak trees do not need emergency pruning, hold off until they’re dormant in late fall or winter. This will help reduce the spread of oak wilt, a deadly fungal disease with no known treatment. Fungal spores are carried by sap beetles, which are attracted to fresh tree wounds and oozing sap on healthy oaks in spring.

Lawns: If the grass is growing and the ground is dry enough, you may begin to mow. Keep the mower set to cut at three and one half to four inches to encourage a thick, healthy lawn.

Houseplants: Pinch or cut off leaves that are yellow (dying) or brown (dead). They won’t be springing back.

General:

Learn how to Garden in Small Spaces at the next Cornell Cooperative Extension of Westchester 2025 Home Gardening Webinar Lecture Series. Wednesday, April 9, 2025, from 10 to 11 am, remote on Zoom, $5.

Speaker: Judy Rozanski, CCE Master Gardener Volunteer, explores maximizing usable space for suburban and urban gardeners. She will explain how to plant in limited spaces, from balconies to yards, and offer tips on choosing appropriate plants, including flowering annuals, perennials, and vegetables.

For more information, contact westchester@cornell.edu or 914-285-4620. See https://s3.amazonaws.com/assets.cce.cornell.edu/attachments/69880/2025_Home_Gardening_Lecture_Series_brochure_2024-10-30-2024.pdf?1730323954

Last updated March 22, 2025