Garden Maintenance Tips for Autumn

It is not necessary to cut down all plants when cleaning the garden in autumn. Leaving some perennial plants standing throughout the winter provides food and shelter for birds and beneficial insects, while removing some plants can help prevent disease and pest outbreaks.

Therefore, the right decision on which plants to keep and which to remove significantly impacts garden health, pest control, and the flowering capacity for the next year.

Leaving perennial plants with seed heads standing in winter provides food for non-migratory birds, while pollinators and other beneficial insects find shelter. Examples include plants like Allium, Aster, large-leaved Lupin, Black-eyed Susan, Chocolate Flower, Coneflower, Goldenrod, Milkweed, Rattlesnake Master, Sneezeweed, and Trumpet Vine.

Most shrubs that bloom in spring develop flower buds on branches that grew the previous year. Cutting them now can remove the buds that would bloom next spring. Therefore, avoid pruning shrubs like Azalea, Rhododendron, Forsythia, and Hydrangea in autumn. If pruning is necessary to shape them or make essential improvements, it is best to do so within two weeks after they have finished flowering.

Ornamental grasses should also be left standing throughout the winter until new growth begins in spring. This provides habitat for beneficial insects during winter, and the swaying grasses keep the garden attractive.

Fallen leaves in garden beds do not all need to be removed. Leaving some leaves in place provides shelter for insects during winter. Once these beneficial insects become active in spring, they help control the population of other insects that damage plants.

It is also advisable not to cut perennial plants with sturdy stems, or somewhat sturdy stems, such as Russian Sage and Lavender, during winter. Their upper parts protect the crown, where the roots and stems join the ground surface, from the cold.

However, some plants must be cut down before winter begins. The dried leaves of Hosta provide hiding places for slugs and other insects during winter. Therefore, Hosta should be cut down to ground level after the growing season ends.

Dried leaves of Iris can also harbor eggs of harmful insects during winter. If not removed, the insects that hatch in spring can damage the plants. To prevent insect infestation next year, it is appropriate to cut and remove Iris leaves now.

Perennial plants susceptible to powdery mildew should also be cut down after the growing season ends. This includes plants like Peony, Bee Balm, and Phlox. Other plants that were diseased this year should also be cut down, and their fallen leaves and other debris should be cleaned from the garden. Doing so reduces the risk of disease-causing agents reaching the soil and spreading to next year's plants. Annual flowers like Zinnia are also highly susceptible to powdery mildew.

Diseased plant parts should not be placed in compost bins. Such debris should be disposed of as separate waste to prevent the disease from spreading to other plants.

While these seasonal suggestions are applicable, dead, broken, or diseased tree branches and shrub stems can be removed at any time of the year. Leaving such parts can affect plant health and pose a risk of injury to people or damage to property if they break during winter storms. Therefore, when cleaning the garden, it is necessary to care for plants according to their nature and condition rather than cutting them all at once.