It’s OK to keep planting in late summer

Are you still feeling the urge to plant, even though we’re in midsummer? It is OK to continue planting at this time of year. Garden staff installs new plants all summer long. The garden centers I have visited still have a broad selection of plants.

The key to success with planting in the heat of summer is to pay close attention to watering new plants, which can dry out very quickly. In general, balled and burlapped trees and shrubs should be deeply watered about once a week, while plants that were grown in containers may need to be watered up to two to three times a week for the first month or so to get them established.

Monitor any new plants you installed over the last few years for moisture. Rainfall may not have been enough to adequately water newer and less established plants. More established plants in dry shade like my Annabelle hydrangeas growing under an oak tree may also benefit from supplemental water to perform their best. My strategy at home is to water established plants when I see signs of stress liking wilting leaves.

Lawn care

Cut your lawn at a height of at least 3 inches during the heat of summer so it will be better able to withstand the hot and dry weather typical in our Midwestern summers. Stronger growing turf will help choke out weeds. A tall cutting height is less important if you water your grass regularly. I do not water my lawn and am very happy when its growth slows down and I can skip a week of mowing.

Coleus

Coleus can slowly overtake and choke out adjacent plants in a container or bed. Simply pinch them back to control their size and thicken up the plants.

Thistles

Thistles are exceedingly difficult to eradicate from the garden, so it is very important to pull them or at least cut them back before they go to seed. It is difficult to get the roots out. If you have a patch that has gone to seed, carefully remove the seedheads before pulling them to avoid spreading the seed around. Put the seedheads in the garbage, not the compost.

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