The Garden Plot: Cold Winter Temperatures Leaves Lingering Impact on Insects & Plants

Long cold winter blots the survival guide for plants and insects

The rhododendron is native to Massachusetts but struggles when taken from tree-covered rich & moist soil.  Add in cold injury and the luscious flower suffers foliage desiccation in dry compacted soil giving it a crispy lifeless texture.

This winter was a cold one – even by New England standards, and as the warmer weeks of spring creep in we tend to forget how frigid some of those nights were. But for some of our landscape plants & pests the impact will be felt for months. Or years.

The Good News:
For many of the non-native invaders like the Hemlock Wooly Adelgid, this cold snap has meant a much higher then average winter time mortality rate for the little buggers. This insect has killed, and will likely kill many more (if not all), hemlocks in the Hilltowns and the Pioneer Valley. However, the rapid onset of sustained cold weather has killed off a huge number of this normally cold hardy insect, which has given a temporary reprieve to recently infested trees .

The Bad News:
Just like the Hemlock Wooly Adelgid, the majority of plants in our landscape and gardens are not native to this area. So what does this mean? A native insect or plant (or at least their ancestors) has evolved in this climate for millennia and has adapted to multiple cold winters. But when you take a plant out of its natural environment and put it in a manufactured one, problems will arise. Take the much loved rhododendron. While it is native to Massachusetts, it is is not native to the dry compacted poor soil of the commercial shopping parking lot down on King Street. In its normal habitat it is found in rich & moist soils under the protection of a tree canopy in eastern Massachusetts. The result of this misplacement is that the plant looks crispy this spring and can look more dead then alive due to foliage desiccation.

The Moral to the Story:
You might think that I will now jump on the “I love all native plants” train. I won’t. Because who is prepared to give up apples, peaches, tomatoes, daylilies, lilacs, honey bees, earthworms, etc.. all non native? Not me. Winter now is defined by unpredictable fluctuations in temperatures and our plants are not adapting quickly enough. So how do we turn this cold winter impact into an opportunity to educate ourselves and collectively cast a cloak of increased invincibility over our plant life? We need to be both strategic in plant and soil choice, and also sensitive in our analysis of tell-tale signs that may occur through sudden temperature changes. Consider the following for starters:

  • Choose plants that can survive in zones 1-5
  • Plant them in a site that mimics their native habitat (i.e. if they want shade, give them shade)
  • Minimize stresses on them (i.e. if thirsty give water)
  • Pray for snow, nothing is a better cold weather insulator for the roots.

Take these considerations and use them as opportunities for your kids to help plan, plant and learn about growing a landscape that is resilient and can thrive year after year. For more information on how cold can effect your landscape, read Effects of Cold on Landscape Plants.

Photo credit: (ccl) Peter Kerr


Jim McSweeney

Jim is a certified arborist, certified horticulturist, licensed pesticide applicator (needed for the application of organic pesticides in MA) & a professional landscape designer with over 15 years experience. He is also the owner of Hilltown Tree & Garden LLC. Jim is on the faculty at the New England Wildflower Society, teaching courses on a diverse range of topics. He lives and works in Zone 5 (Chesterfield, MA) with his family. Once a month here on Hilltown Families you will find timely gardening tips, from a pro in the field, that can be easily used by both avid and novice gardeners, specific to Western MA.

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