Peabody Preserve

Peabody Preserve

Butterfly on coneflower

Butterfly on coneflower

Timely Tips

By Kim Kleman
Master Gardener Volunteer with Cornell Cooperative Extension
of Westchester County

Sept. 17

Perennials: Divide and transplant spring blooming perennials such as hosta, iris, garden phlox and peony, and more. Peonies prefer a sunny location in fertile, well-drained soil. Remember not to plant them more than two inches deep for best blooms.

Flowers: Dig up and store tender bulbs and tubers such as caladium and tender begonias. Wait until frost kills the tops of cannas, dahlias and gladiolus. In warmer zones (USDA Zone 7 or higher) cannas, dahlias and gladiolus may overwinter in the ground. In the cooler areas and microclimates of those zones, an insulating layer of mulch for protection may improve the plants’ survival.

Fruits and Vegetables:Continue to harvest main season crops such as green beans, beets, carrots, cucumbers, greens, tomatoes, peppers, eggplant, summer squash, and planting fast-maturing greens, radishes and turnips. You can use thinnings of young greens in salads. Tree fruit such as apples and pears continue to ripen. Pick pears when they are fully colored but still a bit hard and finish ripening them off the tree. Blemish-free, ripe apples and pears will last 2 to 6-7 months if stored at 32 degrees F.

Trees and Shrubs: Don’t prune unless you find dead, damaged or diseased branches or stems. Removing branches of spring-flowering shrubs that have already set buds, such as azaleas and rhododendrons, forsythia, hydrangea, lilac and others will mean fewer blooms next year. Wait until oak trees are dormant (November through March) before removing branches that may still be alive to reduce the risk of oak wilt.

Lawns:Don’t cut a newly seeded lawn until the grass is at least 4 inches tall. Make sure mower blades are sharp. Dull blades can rip seedlings from the soil and shred the tips of lawn grass blades, causing moisture loss and creating entry points for diseases. Dull blades also increase the amount of fuel consumed by mowing machines.

Houseplants: If plants are not going to fit in their usual indoor space and you don’t have room to accommodate them at their current size, consider pruning or making smaller divisions that will work in your space. Many houseplants respond well to pruning by as much as half. If yours do, you can also plan for extra growth by cutting them back when you put them back outside next summer. You can give away extra divisions to or trade them with friends (using pots you don’t want any more that are wasting space). Donate extra empty containers to a thrift store.

General: To increase the organic matter in the garden soil, add aged manure, compost or leaf mold this month or next. Adult spotted lanternflies (SLF) may be laying eggs on many surfaces and types of objects now, including compost bins, containers, and garden equipment. See a checklist at objects before transporting them elsewhere. SLF is a major agricultural threat that can kill crops (grapes, fruit trees and others) and affect landscape plants. To learn more about the impact of this invasive pest, including how to spot and report any lanternflies you may find, see


Amy Albam
Horticulture Educator/Master Gardener Program Coordinator

Last updated September 19, 2022