Gardening: Give plants time to recover from winter

All bets are off as to what is going to happen as we get further into spring. We haven’t finished figuring out what got damaged in last fall’s drop into winter and now we are facing midsummer temperatures.

Because of the crazy winter weather, we are seeing damage to otherwise reliably hardy plants including roses, butterfly bushes, bulbs like crocosmia and plants that were transplanted last fall. As it turned out, last October was one of the warmest on record. During the first weekend of November, we dropped into what was the fifth-coldest November on record. Because of October’s heat, many plants hadn’t started their dormancy process which draws water down into their roots. When the cold hit, all that water in the stems froze. Because water expands when it freezes, the plant cells were split, killing the branches. Some plants can handle this better than others, so wait until the end of June before taking something out.

Roses will send out new stems, but where the stems come out from will determine if your prized rose is coming back. If the new stems are growing out above the graft point, your rose survived. If the new branches are coming out below the graft, then all you are going to get is rangy, wild rootstock growth that isn’t anything like your pretty rose. In contrast, own root roses should grow new stems that will be true to type.

Many butterfly bushes died to the ground because of the cold and subzero wind chills. The good news is that they should grow new stems from the roots. They might struggle a bit this year, though, so be patient with them and see what comes up.

As I noted in an earlier column, we saw a lot of winter burn on evergreen shrubs like laurels, hollies and some boxwoods. Prune them back to green wood and wait.

We are 2 inches behind in our average rainfall for the year. Even with all the snow we got, the soil is dry under heavy tree cover. I dug out a redbud tree in my nursery bed that is under the edge of a big pine in mid-April and the soil was hardly damp. Elsewhere, I also noticed this under shrubs that held a heavy snow load off the ground that blocked rain from reaching the soil.

Does all this mean it’s time to start up our sprinkler systems? Maybe. If you have a garden that is under trees and shrubs, it would be worthwhile digging down a foot into the soil to see how far down you find moisture. If the dry soil is close to the surface, turn on the system in the area for an hour at each station a couple of times over a week. If we go straight into an extended run of over 80-degree temperatures, it will be time to turn it on for the season. If we cycle between hot and cool weather, be prepared to adjust times accordingly.