Spring Planting by Thomas Hart Benson
Amy writes : When is it safe to plant in Chicago ?
Carolyn answers : A few weeks of good weather and people are eager to get out and plant. March was warmer than April has been thus far and I guestimate that Spring is 3 weeks early this year.
So when is the best time to plant in Chicago ? The answer depends on what you are planting. For instance if you are planting trees and shrubs you can do so as soon as the ground permits digging and before they break buds. I know that some horticulture classes will not teach this but I dare say that the trees and shrubs sitting in pots and a 2-4 foot rootball in the nursery would be much happier planted in the ground and more likely to endure a freeze, or drought .
However, I usually err on the side of caution when planting tender perennials and annuals . In Chicago the old rule of thumb is Memorial Day or late May. I've known some gardeners to plant impatients and other frost-tender annuals in April only to have them killed by late frosts.
In Chicago the dates of the last freeze vary from April 25 to May 20 and we can even have severe frosts after that .