Timely Tips

What to Do in October 2026
Weekly Gardening Timely Tips from
Cornell Cooperative Extension of Westchester County

Oct. 4 – 10

Perennials: In established gardens, finish planting new perennials or dividing those in need. This will allow time for the roots to become established before winter. Remove diseased foliage throughout the garden. Cut back late-blooming hollow stemmed plants, leave at least 12 inches of the stems intact for native cavity nesting bees. New growth can hide these after the perennials emerge in spring. Wait until the ground freezes to mulch the perennials planted this fall. This will help to discourage voles and keep the soil from heaving during a winter thaw and exposing the roots to cold air.

Flowers: If the garden fades by this time of year, perk it up with a final pop of color by planting mums, ornamental cabbage and/or kale, pansies, or other interesting ornamentals for fall interest that may be locally available. Plan ahead and make a list of late blooming plants to fill gaps that could use extra color when a good selection of plants is available next spring.

Fruits and Vegetables: Harvest fall greens, including those that are thinned out to make space for other plants as they become large enough to use. If there are still potatoes in the garden, finish harvesting soon. Keep up with the harvest of main season crops, tree fruit and fall berries that are still producing. Garlic can go in the ground any time this month (the sooner the better). Now’s also the time to dig up and divide rhubarb if it has grown like crazy this summer.

Trees and Shrubs: Continue planting deciduous woody plants now through November, after they’ve shed their leaves to avoid deep planting that can cause failure of trees and shrubs, remove any soil you see over the root flare (the area where the trunk or stems meet the roots) before planting. To prevent settling, make the planting hole as deep as the rootball. Mound an inch or two of soil beneath the plant in the hole to allow for settling. To facilitate root establishment, make the hole 3-5 times the diameter of the rootball and remove all burlap, twine and wires as you refill the hole with the excavated soil. Plants must be well hydrated to develop a healthy root system for successful establishment. Water well to settle the soil, but don’t fertilize.

Lawns: Finish seeding in the next 2 weeks or so to foster turf establishment before the ground freezes. Pick up leaves that are beginning to drop, taking care not to damage or uproot the young grass.

Houseplants should be inside by now. If yours are not, bring them in. Houseplants usually fare better if brought indoors before the heat comes on. (An exception is Christmas cactus, which can stay outdoors until temperatures drop to about 40°F. Winter zonal geraniums can be potted now but can remain outside until early November. Zonal geraniums can even tolerate a light frost. Consider saving some tropicals for next year. Dig them up and place them in individual pots and place them in a cold basement or non-freezing garage. Check once a month to make sure soil remains mildly moist. Begin giving them water and light in early spring and bring outside once frost is no longer expected. Check over wintering plants for pests like aphids, spider mites and whiteflies before you move the plants inside. If you find houseplant pests, contact your local Cooperative Extension for advice. Also check pots and other outdoor items for egg masses of the spotted lanternfly: their eggs can be deposited on many outdoor surfaces in addition to plants. If you live in, plan to travel, or have recently returned from a place where SLF is established, be sure to check

your vehicle and any items kept outdoors for hitchhiking lanternflies or their eggs, and remove all before traveling (a flashlight and mirror may be helpful in hard to see spaces).

Last updated October 4, 2026