Carpenter ants could be nesting inside or outside house

If you find carpenter ants inside during periods of warm weather in spring and early summer, that does not necessarily mean that there is a nest in your home. Try to determine whether the ants are coming from an outdoor or an indoor nest, although this can be difficult.

In winter or early spring, seeing carpenter ants indoors suggests that the ants are coming from a nest in the building. If you see activity later in the year, it is less clear if the nest is in the building. Black carpenter ants can vary in size from ¼- to ½-inch in length. They do not eat wood, but they create tunnels that leave telltale sawdust behind. They are attracted to wood that has been softened by moisture. They also nest in rotting trees, stumps and boards left on the ground. Work with a professional exterminator to eliminate an indoor infestation.

How deep is your tree?

Many trees are planted too deeply. To determine the proper planting depth for your new tree, find the trunk flare (the place where the trunk widens at ground level). If the trunk flare is not showing, open the burlap to find the flare.

Plant the tree higher in the hole and very carefully remove excess soil above the roots to expose the flare. Generally, plant your trees 2 to 3 inches higher than ground level in heavy clay soils.

Don’t amend the backfill that goes back into the planting hole. Do amend the soil at the surface around the tree.

If the root ball appears to be loose, remove the wire basket and burlap after the tree is positioned in the planting hole. Leave the wire basket on if the root ball is very loose and looks like it will collapse if the basket is removed.

Use netting to protect against cicadas

The 17-year cicadas will be emerging soon, so now is the time to install a fine netting on any trees you need to protect.

Focus on very young, small trees (less than 2 inches in diameter) that have few branches. Loosely wrap the trees and attach netting to the trunk to prevent cicadas from crawling up under the netting.

Avoid using insecticides. Most gardeners should simply enjoy this natural phenomenon and not worry about their gardens. Cicadas will not do much damage to healthy established plants.

I plan to continue planting trees and shrubs throughout this year’s cicada emergence.

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