If a plant looks out of place, it's likely a weed
My definition of a weed is a plant that is out of place. A good time to weed is when the soil is moist - the roots come out more easily. It's very important to get weeds out before they go to seed. A small hand weeder or trowel is helpful.
Look for unwanted tree seedlings such as buckthorn, mulberry and box elder that tend to establish themselves in hedges and in the base of shrubs. Look closely and they are easy to spot. In areas where it is not practical to dig out the roots of these weed trees, treat the stump with glyphosate promptly after cutting to kill the root system.
• Prune dead wood out of trees and shrubs as needed. The warmer weather will have made it easier to discern what plants or sections of plants that were killed by winter and need to be removed.
• Practice integrated pest management in your garden to reduce the need to use pesticides. Begin by choosing the proper plant for your site and using good planting practices such as amending the soil with compost and planting at the proper depth.
When possible, select plants that are resistant to common diseases and give them the appropriate care to minimize problems. Monitor all plants carefully for insects and diseases.
If trouble arises, identify the problem and use the least toxic control measure when damage is not tolerable. Timing is also important - apply controls when pests and disease are the most susceptible. Never spray just because you see insects, as some of them might be beneficial or harmless. When you use an insecticide, you kill the good insects along with the bad ones.
Look for more pest and disease resistant plants to replace any plants that have had a pattern of problems in your garden.
When reviewing proposals for chemical treatments, ask questions about target pests and timing to make sure you really need the application to save your money and reduce harmful effects on the environment. Organic pest controls are not necessarily safe for you or your pets, so be sure you understand the products being used in your garden.
• Magnolia scale can kill a magnolia if not controlled. If you treated for it last year (dormant oil treatments are very effective) then you should not need to repeat the treatments this year. Monitor the tree and treat when there are scale insects present.
• Tim Johnson is director of horticulture at Chicago Botanic Garden, chicagobotanic.org.