June is a good time to focus on weeding and mulching

Weeds are having a field day in my garden at home. This is a good time to focus on weeding to prevent annual weeds from setting seed and increasing your work next year. Garlic mustard is a very invasive biennial weed.

Biennial weeds grow close to the ground in the first year, and then grow into taller plants the second year. The taller garlic mustard plant has white flowers and will set lots of seed if allowed. I have started pulling first-year plants out of my garden.

Proper mulching

Trees planted in lawns can benefit from a mulched ring to reduce competition with grass roots and to keep mowers and weed whips from damaging trunks. If the tree is small, mulch out to the drip line of your tree.

If this is not feasible, extend the mulch as far as you can. Even a 6-inch-wide mulched saucer can protect tree trunks from serious damage. I see many trees with soil and mulch mounded up around the trunk. This should be corrected in your garden.

Mounded soil and mulch around trunks is unattractive and can cause rotting at the base of the tree.

A guiding hand

Monitor and train vines such as clematis on their supports. It is best to do this regularly 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.

Wider at the bottom

June is also a good month to shear your hedges. Prune formal hedges slightly wider at their base than at the top. This ensures that the sides of the hedge will receive equal sun exposure and helps keep the foliage full from top to bottom.

Many hedges in the home landscape are not pruned properly and are wider at the top than the base. Pruning hedges in June will help create a denser hedge. Since you can expect more growth, plan on shearing your hedges again in July.

Remove dead wood

Prune dead wood out of trees and shrubs as needed. If there are no leaves on a branch by now, it is probably dead. Although cicada damage from last year is generally not a major concern, do prune out damaged areas.

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