Winter Injury

photo MSU

For the avid plants person spring is the most thrilling and heartbreaking time of the year.

It is at this time that we get to see which of our old friends has made it through winters harsh blast.

While some trees and shrubs may look as though they are headed to the great hereafter, caution is always the rule at this time of year. More than one plant, having been given last rites, has literally come back from the roots on the compost heap! Take caution before writing a survivor off.

To understand how plants succumb to the ravages of winter we must have a basic understanding of plant physiology. Leaves are incredibly useful plant organs are notoriously fragile when it comes to freezing. Hardy trees and shrubs generally lose these most tender parts in preparation for winter. Those that don't lose their leaves have thick waxy cuticles, or skins, that prevent dessication. Dying out over winter has led to the demise of many a plant. You don't need a microscope to see how thick and durable a spruce or pine needle is, just hold it in you fingers and break it.

If you failed to water your evergreens last year they may be looking a little burnt out at this time.

Check to see if the buds are swelling and pinch the bark to see if its supple and alive. If you scrape back the bark with your finger nail you may see green, it may not be the end for this tree, wait a few weeks and see what happens.

Arborvitaes, junipers and other scale leafed evergreens may look scorched at this time of year, again wait a few weeks before you throw these babies out with the bath water. In most cases simple preparation in the fall could have prevented some if not all of these types of injuries.

Watering well until freeze up is a good strategy. Antidesicants, waxy sprays applied in the fall, are good for established plants that can have problems as well as fall planted evergreens that have yet to establish.

Late summer fertilization of evergreens is not recommended as it may delay the onset of dormancy and leave trees and shrubs susceptible to winter injury. Wait until trees are in the process of becoming dormant before fall fertilizing.

As for the trees and shrubs that are suffering from the effects of last winter? They should be watered well and monitored for signs of improvement. A small amount of fertilizer or better still an organic soil enhancer like pulverized liquid sea kelp can help with root growth and speed recovery.

Don't over water trees that have been winter injured but don't let them dry out completely either.

Use your finger to see if the soil in the root zone is dry. Be patient you may save an old friend from the compost heap.