I am sitting here at my desk with a hot mug of tea and its snowing! The state of the weather always seems to make it into our casual conversations.
It’s a broad experience that affects us all and is the common ground that allows us to connect with others easily.
This year, I feel I have done my share and then some when it comes to chatting about the weather.
Snow in March? What can I say other than Mother Nature does as she pleases.
The prolonged winter and incredible cold temperatures in December are making themselves known among broad leaf evergreens this year.
I have had a few people call worried their shrubs had contacted some type of disease. Upon closer inspection it seems to be a type of winter injury or winter burn, which is also known as foliar desiccation.
Winter burn occurs when the soil is frozen or very dry for prolonged periods of time. The plant roots cannot take up water to replace that which evaporated from the leaves.
Leaves are always transpiring, even in winter, and as they transpire they give off water. The extreme cold stops roots from most of their ability to absorb water. This results in leaves having a water deficit and you will notice they wilt or turn brown. Sometimes there appears to be a mottling effect across the shrub
I’ve noticed the damage in smaller leafed rhododendrons and azeleas (even well-established older shrubs), as well as pieris, laurel, viburnum and arbutus unedo. This kind of winter damage is not limited to the ones I have happened to spy; you may also see it in boxwoods, holly, euonymus, etc.
Evergreens in sunny, dry and windy locations may be more severely affected. As the temperature warms the symptoms become more visible.
In addition to the wilting and browning there may even be considerable dieback. But don’t panic.
If only the leaves are affected, the plant will send out new shoots and leaves in the spring. If the shoot tips are dead, they will need to be cut back to live tissue (it’s still a bit early to do this). You may lose some blooms off early spring flowering shrubs, but patience will show that these garden workhorses will definitely bounce back.
If you are uncertain whether a twig is dead or alive, I always like to use the “scratch test.” Scratch the bark with your fingernail. If the tissue beneath is brown, that section of the twig is dead. If the section you scratch is pale green or white, the twig is till alive and no pruning is needed.
One tip you may want to note is that because of winter stress it will be important for the long-term health of your shrubs to fertilize this spring.
It’s still early days on the gardening front. Observe your plants and be patient.
Wait until warmer temperatures arrive to herald in the gardening season.