Gardening Tasks For Late Fall

Fall is one of the best times to work in the garden. Cooler temperatures make outdoor projects more comfortable, many plants can still establish roots before winter, and the end of the growing season gives you a chance to see what worked well and what you might want to change next year.

Your exact fall schedule will depend on your climate and first frost date, but common jobs include harvesting, continued watering, dividing or moving plants, cleaning up diseased material, leaving useful seed heads standing, planting, mulching, protecting tender plants, and preparing containers for winter.

Finish Harvesting Vegetables And Herbs

Continue harvesting vegetables and herbs as the growing season winds down. Some crops tolerate light frost better than others, so the first chilly night does not necessarily mean everything needs to come out of the garden at once.

Tomatoes that have begun changing color can often finish ripening indoors. Winter squash should generally be harvested before a hard freeze, while cool-season crops such as kale and carrots may tolerate colder conditions.

Fall is also a good time to harvest and dry herbs or preserve produce for later use. Follow current university Extension or other tested food-preservation guidance when canning, freezing, or otherwise preserving food.

Keep Watering As Temperatures Cool

Cooler weather does not automatically mean plants no longer need water. Trees, shrubs, perennials, and other new plantings continue developing roots in fall as long as soil temperatures remain suitable.

Check soil moisture and continue watering when rainfall is limited, especially around newly planted trees and shrubs and evergreen plants. Trees and shrubs that enter winter severely dry can be more susceptible to winter injury.

In colder climates, a thorough watering in late fall before the soil freezes can help woody plants enter winter with adequate soil moisture.

What Should You Cut Back In Fall?

Fall cleanup does not need to mean cutting every perennial to the ground. A better approach is to decide which material should be removed for plant health and which stems can remain useful through winter.

Plants that experienced significant disease problems during the growing season are good candidates for fall cleanup. Removing affected stems and foliage can reduce the amount of infected material remaining around the garden.

Perennials such as bee balm, garden phlox, peonies, Shasta daisies, and speedwell may be cut back after they decline, particularly if the foliage was affected by disease or you prefer a tidier appearance.

Do not compost plant material with serious disease problems unless your composting system reliably reaches temperatures capable of destroying the pathogen. When in doubt, dispose of diseased material separately.

What Should You Leave Standing Until Spring?

There are also good reasons not to make the fall garden perfectly tidy. Healthy perennial stems, ornamental grasses, and seed heads can add winter interest while providing food and habitat for birds and other wildlife.

Seed heads from plants such as coneflower, black-eyed Susan, sedum, and many ornamental grasses can remain attractive long after flowering ends. Birds may also feed on the seeds throughout fall and winter.

Many gardeners leave ornamental grasses standing until late winter or early spring. Their foliage adds texture to the winter landscape and can help protect the crown of the plant.

Evergreen or semi-evergreen perennials such as hellebores, coral bells, barrenwort, and some groundcovers generally should not be cut back simply because fall has arrived.

For bulbs and bulb-like perennials, allow foliage to yellow and die back naturally before removing it. Green leaves are still photosynthesizing and storing energy for future growth.

Divide And Transplant Perennials

Early fall can be an excellent time to divide many spring- and summer-blooming perennials. Cooler temperatures reduce transplant stress, while warm soil can still support root growth.

Plants that have become overcrowded, developed a declining center, outgrown their space, or simply need to be moved may benefit from division.

Peonies, Siberian iris, daylilies, hostas, yarrow, bee balm, and several other perennials can be divided in fall when conditions are appropriate. The ideal timing varies by plant, so check the needs of the particular species before digging.

Some plants dislike division or have deep root systems that make moving difficult. False indigo, for example, develops a substantial root system and is generally better left undisturbed once established.

Water divisions after replanting and keep the soil from drying excessively while roots become established.

Plant New Perennials, Shrubs, And Trees

Fall can also be an excellent planting season. Cooler air temperatures reduce heat stress, and soil often remains warm enough for root development after top growth begins slowing.

The amount of establishment time needed before winter depends on the plant and your climate. Gardeners in colder regions should generally plant earlier than gardeners in mild-winter climates.

Continue watering fall-planted material until dormancy and freezing soil reduce the plant's water needs.

Plant Spring-Flowering Bulbs

Fall is planting season for many spring-flowering bulbs, including tulips, daffodils, crocus, and ornamental alliums. These bulbs require a period of cool temperatures before they can flower normally in spring.

Planting time varies by climate, but bulbs are generally planted after soil begins cooling and before the ground freezes solid.

Dig And Store Tender Bulbs And Tubers

Not every bulb or tuber can remain outside through winter in every climate. Plants such as dahlias, gladiolus, cannas, caladiums, and elephant ears may need to be dug and stored if they are not hardy where you live.

Digging time and storage requirements vary by plant. In general, tender underground structures are cleaned, allowed to dry as appropriate, and stored somewhere cool but frost-free until planting time returns.

Hardy bulbs and perennials should remain in the ground rather than being dug simply because fall has arrived.

Save Seeds — And Leave Some For Wildlife

Fall is a good time to collect mature seeds from plants you would like to grow again. Seeds from many flowers, herbs, and vegetables can be cleaned, dried, labeled, and stored for future use.

You do not need to collect every seed head. Leaving some intact can provide food for birds and allow desirable plants to reseed naturally.

Keep in mind that seeds collected from hybrid cultivars may not produce offspring identical to the parent plant.

Evaluate Your Garden Layout

One of the most useful fall gardening jobs does not involve pruning, digging, or hauling mulch. Take a walk through the garden and evaluate how everything performed.

Look for plants that:

• Have outgrown their available space.
• Are being crowded by neighboring plants.
• Receive too much or too little sunlight.
• Stay too wet or dry for their preferences.
• Would look better somewhere else in the landscape.

Also consider the overall design. Is a bed missing height, texture, repetition, seasonal color, or a clear focal point? Are mature plants hiding shorter specimens? Did one combination work particularly well?

Write down these observations while they are still fresh. Some plants can be moved now, while others are better added to your spring project list.

Clean Up Diseased Material And Weeds

Fall cleanup should focus first on material that could create problems next year.

Remove weeds before they produce additional seed, and clean up foliage or stems affected by serious disease. Healthy plant material can often be composted or left standing when it provides wildlife or winter-interest benefits.

There is no need to remove every fallen leaf from every garden bed. Leaves can add organic matter and provide overwintering habitat, although thick, matted layers may need to be redistributed or shredded so they do not smother smaller plants.

Keep heavy accumulations of leaves from matting over turfgrass.

Refresh Mulch For Fall And Winter

Mulch helps conserve soil moisture, suppress weeds, and moderate fluctuations in soil temperature.

For trees and shrubs, maintain an appropriate mulch layer over the root zone while keeping mulch away from trunks and woody stems.

For winter protection of perennials and bulbs in cold climates, timing is important. Heavy winter mulch is generally most useful after the soil begins to freeze because its purpose is to reduce repeated freezing and thawing rather than keep plants actively growing.

Shredded leaves, pine needles, straw, compost, and wood-based mulches can all be useful depending on the planting and purpose.

Improve Garden Soil

Fall can be a convenient time to add compost or other organic matter to beds that need improvement. Organic amendments can remain in place through winter and make spring preparation easier.

Avoid automatically adding lime, fertilizer, or other amendments simply because the season has changed. If you are concerned about soil pH or nutrient levels, a soil test can help determine what the bed actually needs.

Fall is also a good time to consider cover crops in empty vegetable beds where your climate and planting schedule allow them.

Prepare Containers For Winter

Remove declining annuals and vegetable plants from seasonal containers once they are finished. Healthy material can usually be composted; diseased material should be discarded appropriately.

Container plants that are not winter-hardy in your climate may need to be brought indoors, moved to protected storage, or treated as annuals.

Empty decorative containers when freezing moisture could damage the pot. Ceramic, terra-cotta, and other porous materials can be particularly susceptible to freeze-thaw damage when left filled with wet soil.

Used potting mix does not necessarily need to be thrown away, but it often benefits from refreshing before reuse. Do not reuse potting mix from plants that experienced serious soil-borne disease problems.

Prepare Tender Plants For Frost And Winter

Before freezing temperatures arrive, decide which tender plants need to come indoors and which landscape plants might benefit from temporary frost protection.

Frost cloth, row cover, burlap screens, plant guards, and other barriers can all serve different purposes. Newly planted trees may also need trunk protection where rabbits, voles, or deer are common.

Avoid assuming that a south-facing wall is always the safest winter location. While structures can create warmer microclimates, reflected winter sun can also increase temperature fluctuations and winter injury on some plants.

Make Notes Before The Garden Goes Dormant

Fall is one of the best times to evaluate the garden because the entire growing season is still fresh in your mind. Make a list of plants you want to move, combinations you want to repeat, problem areas you want to fix, and plants you hope to add next year.

You do not need to finish every garden project before winter. Concentrate on jobs that protect plant health, take advantage of good fall planting conditions, and make next spring easier.

And don't forget to enjoy the season. Fall flowers, colorful foliage, seed heads, grasses, and changing light can make this one of the most beautiful times of year in the garden.