June is a good month to shear your formal hedges. Pruning hedges in June will help create a denser hedge. There likely will be more growth, so plan on shearing again in July.
Shear hedges so they are slightly wider at the base than at the top. This helps to keep the foliage full from top to bottom by exposing each whole side of the hedge to the sun. Many hedges in the home landscape are not pruned properly. They are usually wider at the top than the base.
Deadhead hybrid roses as soon as the flowers fade. Many shrub roses, however, are self-cleaning and don't require deadheading. When in doubt, lightly prune old blossoms to keep plant looking attractive. Do not deadhead any roses that are being grown to produce hips; the flowers must remain to turn into fruit.
Mowing is one way to control weeds if you are trying to establish a large natural prairie area in your garden.
In their early years, native plants typically develop their roots, not their foliage or flowers, which gives weeds the opportunity to gain a foothold. Mow weedy areas now, setting the lawnmower blade as high as possible, to cut back the weeds and keep them from choking out the native plants. In small areas, weed by hand. You also can carefully spot-treat weeds with an herbicide.
Monitor and train vines such as clematis on their supports. It is best to do this on a regular basis to direct the vines where you want them to go. Once they have been allowed to grow out for a few weeks without support, it will be difficult to train them back up.
Prune dead wood out of trees and shrubs as needed. You may be seeing some plant damage from last year's drought.
• Tim Johnson is director of horticulture at Chicago Botanic Garden, chicagobotanic.org.