Perennials, trees and shrubs have an advantage when planted in fall. As foliage and flower production wanes, root activity increases. Plants are able to establish strong, healthy roots before the ground freezes and are then able to divert most of their energy into spring leafing and flowering.
- Evergreens and trees may be fertilized with a half-strength, slow-release, granular fertilizer once plants have gone dormant but before the ground freezes (usually mid to late October).
- Evaluate the performance of this year’s plants. Make notes or take pictures so you have something to reference when shopping for new plants next spring.
- Check for snail & slug damage. Snails & slugs are laying eggs right now. Apply snail bait or diatomaceous earth to soil, not plants.
- Spray deer & rabbit repellants now to discourage grazing as food supplies become limited. Continue through winter as needed.
- Cleaning up weeds on a continual basis will greatly lessen your weeds next spring especially if they’re pulled before they have a chance to drop seeds.
- Dispose of disease- or insect-laden leaves & plants. Don’t compost them. Cleaning the garden goes a long way toward reducing problems next year.
- Continue deadheading annuals for continuous flower displays.
- Harvest vegetables frequently so that plants remain productive.
- Dig up tender bulbs before foliage is damaged by a hard frost.
- Bring in tender tropicals before temperatures dip below 45º F. Check for insects & treat before bringing inside. Repot, if necessary.
- Plant cold-tolerant pansies, dianthus and ornamental cabbage & kale.
- Starting in October (when soil temp. is 60º F or less), plant bulbs of spring bloomers such as crocus, anemone, daffodils, hyacinths and tulips in well-drained soil, about three times deeper than the diameter of the bulbs. Add bone meal or bulb tone to encourage strong root development.
- Oriental poppies and bearded iris can still be divided in August. Peonies and lilies should be divided or transplanted in September. Other crowded perennials that bloom from early spring to late June can be divided now. Perennials that bloom after late June are better moved/divided in spring. These perennials can also be divided in fall provided foliage is cut back by half to prevent major wilting due to the reduction of roots. Be sure to water thoroughly after transplanting.
- Continue deadheading late blooming, daisy-type perennials such as echinacea, rudbeckia, asters and heliopsis. These flowers will continue to bloom for weeks if the plants aren’t allowed to set seed.
- Plant hardy mums for fall color. Be sure to plant in a well-amended and well-drained soil. Don’t remove dead foliage; it helps insulate the root area. Mulch well after the ground freezes. Check the root area periodically over the winter for heaving; lightly tamp back in place to prevent roots from drying out.
Trees and shrubs:
- Fall is an ideal time to shop for and plant new trees and shrubs.
- Choose trees and shrubs with edible berries to provide meals for wildlife, or select for bright splashes of fall foliage.
- Continue watering new plantings. New shrubs & trees as well as broadleaf evergreens such as azaleas, hollies and rhododendrons should be watered thoroughly one last time around Thanksgiving.
- Spray an anti-transpirant such as Wilt-Pruf or erect screens around shrubs that are sensitive to drying winter winds.
- Many deciduous shrubs and trees are best pruned in the winter after their leaves have fallen. It’s easier to see where you might need to thin and/or cut back to maintain the shape of the plant. Do not prune spring blooming plants in the fall. Wait until after they’ve bloomed & prune within 3-4 weeks.