Time to display fall flower arrangements

Early-season mums are now available in garden centers. If you plan to plant them in a shady location, look for plants that have the flowers partially open. Otherwise, try to buy plants that are just starting to show color for the longest display period.

Season-extender chrysanthemums will be available later in the season to extend the display.

• Autumn is an alternate time to core aerate to reduce soil compaction and thatch if you did not aerate your lawn last spring.

Core aerating once a year is enough for most residential lawns with normal use. High-use lawns benefit from being aerated twice a year.

Aerating also provides an opportunity for overseeding to help improve and thicken up your lawn. Keep the seed moist for good germination. Core aerating is best done when the ground is somewhat moist.

Leave the soil and grass plugs on the lawn to break up and filter back down to the soil level. The plugs typically break down in seven to 14 days.

Mark sprinkler heads and light fixtures in the lawn to avoid damaging them.

• Divide perennials that bloomed in spring and summer as needed. This is best to do early in the month so plants have time to establish before cold weather sets in. Mulch the newly planted divisions to help them get established this fall and prevent frost heaving in the spring.

• Provide supplemental watering for plants you have installed over the last couple of years because of the hot and dry weather earlier in the month. Monitor older plants in your garden for signs of drought stress, which include wilting leaves, off-color foliage, early fall color and dropping leaves. These plants will also benefit from supplemental watering to help sustain them until the rains return along with the typical cooler fall weather in September.

• Tim Johnson is director of horticulture at Chicago Botanic Garden, chicagobotanic.org.