Containers, baskets may need a fertilizer boost

If the plants in your containers or baskets are looking stunted or have leaves that are yellowing, they may need supplemental fertilizer. The frequent watering required for containers and baskets can leach nutrients out of the growing medium. Use a water-soluble fertilizer as needed to perk them up.

It is best to fertilize the containers and baskets when the soil is moist and not dry. Fertilizing plants that are very dry can result in damage to their roots.

If the new growth at the tips of your pine’s branches has turned brown, a disease called Diplodia tip blight may be the cause of the damage. Since the infection occurs in the spring, it is too late to spray fungicides now. Prune out dead tips in dry weather to reduce the spread of infection next spring. Whenever you prune diseased branches, disinfect your pruners in between plants. I use Lysol disinfectant.

Before you use any insecticide, it is important to identify the insects on your plants to determine whether or not the insect really is a problem. If it is, try to assess whether the damage being done warrants control. Just because insects are feeding on the plants does not mean it is necessary to use an insecticide. Some insects are beneficial and help control other insects naturally.

If a pest you have identified is causing significant damage, it is important to use a correct control with proper timing. If a variety of treatments are available, use the least toxic control possible.

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