'Nothing serious should have occurred' due to mild winter

SPECTRUM/Richard Schipul for Home & Garden column, April 2012
SPECTRUM/Richard Schipul for Home & Garden column, April 2012Contributed Photo

Due to the unusually warm winter, many clients and friends have asked what effects this past winter will have on plants and gardens.

Here is my prediction for the upcoming gardening season.

You would think a warm winter would be good for plants? Just as extremely cold weather can wreak havoc on plants, so can an abnormally warm winter, especially during a winter with little precipitation.

Plants of all types were thoroughly confused this winter, from the cherry tree I saw blossoming in February to the daffodils flowering at a time when they are usually in their mid-winter slumber.

The good news is nothing serious should have occurred to affect the long-term health of your plants.

The bad news is spring flower displays shouldn't be as showy as they typically are.

Some plants are well ahead of schedule while others are still running on their normal schedule despite the weather.

It's hard to imagine, but some studies on plants have shown some species have their own internal calendars.

We can have a warm winter but, if the day isn't the right length, a plant will remain dormant a little later than if the day is the right length, no matter what the temperature.

Some plants have the capability to track weather and will be slow to break dormancy unless the winter season's cold requirement has been met.

A plant's calendar will monitor weather and regulate dormancy whether the winter temperature is 5 degrees or 65 degrees. Because of this, holding off on spring pruning until a plant is fully leafed out might be a good idea.

Despite the weather, branches that might look dead may still be dormant. Check for life by cutting off a small branch or rub off some bark. If green tissue exists, the tree is fine.

Spring flowering shrubs bloom on last year's growth. Those flower buds are subject to all the crazy weather New England experiences.

During winters when we get warm weather, a plant's buds can swell and start to open. This premature growth is fine if we continue to receive moderate temperatures.

Trouble sets in when the temperature dips back to sub freezing. Once that occurs, flower buds are damaged and, come spring, will not flower.

A lot of spring flower buds in both trees and shrubs began to swell and were then damaged by the false sense of spring followed by a couple of days of more normal February and March cold.

Warm winter days followed by nights below freezing can also wreak havoc on thin barked trees.

On warm winter days sap begins to flow. As night time temperatures drop below freezing the sap freezes, then expands to the point where it can split bark, causing what is called frost crack.

Nothing can be done once the split occurs other than to give the tree time to heal. Frost crack isn't detrimental to tree health but it does diminish the look of the tree and provides an easy access point for insects and diseases.

A concern from this past winter, beyond the warm temperatures, was the lack of precipitation.

You might notice some damage from winter dessication on broad-leaf evergreens.

Dessication occurs when broad-leaf evergreens lose water through evotranspiration quicker than it can be replaced.

If you notice some off color or dead branches, you'll need to prune and fertilize the plant to aid recovery.

Also, think about spraying your broad-leaf evergreens with an anti-transpirant every winter to prevent future damage.

One good thing to come of this crazy weather is that the late fall and mild winter encouraged root growth in all plants, including turf.

A healthy root system helps fend off insects, diseases and drought stress.

Happy gardening!

Richard Schipul holds degrees in landscape architecture and horticulture, is a nationally certified landscape designer and the owner of Designing Eden LLC in New Milford.