It’s time to get to work in the garden. Here is a checklist of things you should be aware of this month.
Woody plant care
May is the month to plant trees and shrubs. Early morning planting will improve your chances of success and prevent heat and transplant shock. Watering becomes an important part of new plant maintenance. Thorough and gentle watering at planting time and supplying 1 inch of water a week for the first year will get your new trees and shrubs off to a good start. Mulch new transplants to conserve moisture.
Pruning and deadheading of some shrubs will need to be done this month. Spring-flowering shrubs should be pruned immediately when bloom ends. Azaleas, rhododendrons, small magnolias, viburnums and forsythia are examples of shrubs that benefit from pruning at this time. Increased flowering on your lilacs will occur next year if spent blossoms are removed after bloom this year.
During May, decisions may have to be made by home gardeners regarding the status of their roses. Some roses may recover from the severity of the winter while others will not. You will have to consider removing them and possibly planting new ones.
If your roses survived and buds are appearing, it will be time to fertilize them with a 20-20-20 liquid fertilizer. If aphids are seen on your roses as they mature, you can spray them with a strong stream of water.
Climbing roses should be encouraged to develop lateral, flower-bearing canes.
Annual and perennial care
The average last frost date for our area is May 15. Cold tolerant annuals such as pansies, snapdragons and stocks can be planted after the 15th. Tender annuals such as impatiens, begonias and coleus will be more safely planted after Memorial Day.
Perennials will begin to appear as temperatures improve. May is a good time to check your perennials for winter damage and also a good time to decide which perennial clusters have grown too large and need to be divided.
Summer and fall bulbs can be planted this month.
The planting of lotus, water lilies and other pond plants should not take place until the water temperature has reached 65 degrees.
Lawns should be mowed at 2 to 2 1/2 inches. Dry clippings can be left on the lawn to return nutrients to the soil.
Lawns can be fertilized if necessary in mid-May, but the preferred time to fertilize is in the fall.
Fruit and vegetable care
June-bearing strawberries should have their flowers removed the first year in order to develop a stronger root system.
Everbearing and day-neutral strawberries need to have their early flowers removed. Flowers occurring after July 1st can be left on for later season developing fruit.
Your families favorite cool-season vegetables can be planted this month including spinach, lettuce, radishes and peas.
Tomatoes, peppers, eggplant and some squash are cold-sensitive and are best planted at the end of the month.
Indoor plant care
Houseplants can gradually be moved outside to protected areas away from wind and direct sun. Do not move them outside until night temperatures reach 55. It is a good idea to be especially careful of indoor plants that are tender annuals or tropicals.
It is immediately apparent as we drive around local neighborhoods that our beautiful evergreens have been seriously damaged by this year’s long, severely cold winter. Winter winds also have been desiccating our evergreen trees and shrubs. Long periods of snow cover have resulted in the deer having to feed on evergreens as their ground browse was unavailable.
If your evergreens are completely brown, they will not recover. Again, you will need to consider removing them and possibly replacing them with new trees and shrubs. If some green needle growth is visible, stems are green when scratched and buds are present, it is possible that they might recover. By June, you should be able to make a decision about whether or not they have survived.
• The Master Gardeners are available to answer questions from 9 a.m. to noon Monday through Friday at the University of Illinois Extension DeKalb County office in the Farm Bureau Center for Agriculture, 1350 W. Prairie Drive in Sycamore. Call 815-758-8194 or email DeKalb_mg@extension.uicu.edu. Walk-ins are welcome.