I was a little too anxious and planted a potted Korean dwarf lilac and hydrangea in the ground today. Both are about a foot tall. I’ve placed mulch around the roots to protect them but should I dig them back out to wait until mid May? I’m in downtown Toronto
Both dwarf Korean lilacs and hydrangeas do well in the Toronto climate; however, if leaves are already on these plants, you may be planting them outside a bit early. It isn’t the roots that you should worry about as there wouldn’t be a hard enough frost at this point to damage the roots. It is the leaves that may be a concern as the temperatures will be dropping later this week. It may be that your plants haven’t been hardened off against the changeable outdoor conditions. That not only includes the temperature but the harsh winds that we are witnessing today (April 19th). Hardening gradually introduces the plants to outside conditions over a period of time by ever-increasing periods of exposure. It should only take a few days but is important when exposing indoor plants to the outside environment.
If they are in a location protected from the wind and close to a sunny wall, they should be fine and should do well if there is no frost or intense wind.
If a frost is called for, you may either want to bring those plants in or protect them with a canopy of plastic or paper that will endure the frost period. Remember to remove it immediately after the risk of frost has been lifted so that the plant isn’t over heated in its tent.
Water them well.