As September ushers in the changing seasons and offers a period of rest for the garden, there are still a few essential tasks to complete this fall. Taking these steps will help ensure your garden thrives with health and beauty come spring.

Cut back plants (or not!) 

Any diseased or insect-infested plants should be removed and destroyed (not composted) before winter to avoid spreading in the garden. Additionally, remove hosta leaves once damaged by frost, as they can harbor slug eggs that might overwinter and cause problems later.  

Instead of cutting all the plants to the ground this fall after everything turns brown and crunchy, consider leaving some plant material standing for winter interest and overwintering insect habitat. Ornamental grasses and some dried seed pods add movement and structure to the garden, creating a beautiful display, especially when dusted with snow. Many beneficial insects use dried leaves and hollow stems for shelter during the winter months.

Overwintering plants indoors 

In central Illinois, the first frost typically arrives in mid-October, though it can come earlier. To save your favorite garden plants, move them indoors before a damaging frost. With some attention and care, overwintering your top garden performers indoors will save money and fill your garden next spring. Tender perennials, tropical plants, and some herbs easily overwinter in conditions preferred by houseplants.  

Select only healthy specimens for overwintering and carefully inspect each plant for signs of pests and disease. Rinse the leaves with a stream of water to remove tiny hiding insects and consider treating plants with insecticidal soap as a precaution.  Dig up the entire plant, taking care to keep most of the root system intact to minimize stress. Pot the plant in a container with fresh potting soil and cut back the foliage by one-third to help the plant focus on root repair rather than maintaining mature top growth. Care for overwintered garden plants just like a houseplant—place in a sunny location, water when dry, and supply a source of humidity, such as a shallow pan of gravel and water underneath the container.

Planting spring bulbs in the landscape 

The best time to plant spring bulbs is from late September through October to allow sufficient time for a good root system to develop before winter. Spring bulbs need a cold period to guarantee a spring bloom. Consider planting in large drifts of color to make a dramatic statement in the landscape. Mix them in with other perennials and shrubs to screen the foliage after blooms fade.  Also, make sure to plant bulbs two to three times their length. (Measured from the bulb base to the bulb tip.) Bulbs should be spaced six to 12 inches apart to allow space for bulbs to multiply by producing offshoots. If the fall is unseasonably dry, water weekly until the ground freezes. A light, 2-inch layer of mulch added to the soil after planting will minimize soil temperature fluctuations in winter and converse soil moisture.