Goodbye – Cold Weather

I usually like putting pictures in with Leif’s articles – but this week it would have to be a picture of a sad looking bleeding heart that started to come up the end of March or our daylilies here at the nursery on the hillside which don’t look very happy – so – no picture. The phone rang over and over this past week or so with questions like “What is going to happen to my perennials that started to come up?” This article will be in the April 14th – Northfield News.

“Cabin fever? Can anybody relate? Yes, the harbingers of spring were with us ever so briefly a couple of weeks ago, but we can now be sure that we do indeed live in the frozen northland.

Most of us feel stir crazy and are concerned about the perennials that started to emerge before the unusual cold of the last ten days. While there’ll be a few casualties and the already emerged foliage may be damaged, in most cases, the plants will rehabilitate with assistance. As these perennials push additional new growth, you may need to trim off some of the frost damaged parts which will mean a reduction or absence of blossoms. Wait to do the pruning until
you can see clearly which parts are dead.

The buds on many trees and shrubs swelled during the late March warm period and have essentially been at a standstill the last couple of weeks. Here again, there may be some damage to the buds but I anticipate less than on the already emerging perennials. With trees and shrubs, it will take several weeks or more to really determine how much damage occurred during the April cold snap. Don’t rush to prune because you think something might be damaged. On the other hand, if there are trees and shrubs that you were already planning to prune for size reduction or to structurally prune, go ahead and do so, but don’t prune off parts because you think they may have suffered frost or freeze damage. Be sure to see observable damage before you remove parts of the plant unless that part needs to be pruned off whether or not it is damaged.

Most plants hardy for our Zone 4 climate are capable of withstanding pretty extreme temperature fluctuations in weather and most should be just fine. This could be the year we find out if some of our Zone 5 plants that we’ve been experimenting with can handle our changing climate.

One of the aspects of climate change that is notable is not just a general warming of our climate, but greater extremes. For this reason, if you wish to experiment with Zone 5 plants, I’d still recommend that you position these plants in fairly protected areas. Another thing to consider with Zone 5 plants is that the fundamental requirements for optimum plant growth should be more carefully provided than for Zone 4 plants. If a Zone 4 plant is a little stressed from inadequate drainage, a Zone 5 plant in the same place would suffer more from poor drainage due to being marginally zone hardy. This is the fact that makes it more important to choose a spot with good drainage, fertility and sunlight – not to much – not to little when experimenting with Zone 5 plants.

While the cold and damp soil conditions might push back or prolong spring planting of row crops, these cool soil conditions really don’t present much problem with planting trees and shrubs. As long as our soil is dry enough to dig without producing clumps and clods, you can go ahead and comfortably plant trees and shrubs.”