TREES: The Real Superheroes of Winter

Screen Shot 2018-01-05 at 11.02.51 AMThe entire east coast is covered in snow, iguanas are freezing and dropping from trees in South Florida, single digit temps have us all hunkering inside and somehow, the trees all prevail. Have you ever stopped to think just how trees and plants survive prolonged freezing temps and still manage to bloom in the spring? The answer is that science is truly amazing and trees are pretty good at preparing for the winter.

The first step occurs in autumn, when low temps and longer nights act as a warning signal for trees to store their nutrients, slow down on producing chlorophyl and drop those leaves!  The tree is preparing to become dormant.  What most people don’t realize, is that dormant doesn’t actually mean inactive, instead the tree strategically turns on the genes that will help it survive the cold and turns off those genes that are associated with growth.

When the temp drops to moderate freezing (20s and 30s) the trees have a very complex way of controlling where the ice will form within their makeup.  The tree will often separate out their more vulnerable cells, allowing them to become the nucleator of ice growth.  Since moisture is attracted to ice (think about frost growing in your freezer) ice will continue to form in these concentrated areas, leaving the remaining more important cells protected.

But what about when the temp gets dangerously low, like the 5-10 degree range we are experiencing now? Trees in much colder climates have a final defense against the cold that is truly remarkable.  Trees sensing an extreme drop in temperature will begin producing protein molecules and sugars that will lower the freezing threshold for liquids inside the tree’s cells.  These sugars act just like anti-freeze, turning the cell liquid into a really dense, concentrated solution, thick like molasses, that literally cannot freeze. The tree also produces more molecules that will act as ice nucleators, but smartly only grows them in the intercellular spaces, protecting the cells from ever freezing and drying out.  “At this stage where trees are fully cold-acclimated, you can put them into liquid nitrogen and they would survive” says Sally Aitken, Forestry Professor at the University of British Columbia.

So now that you’ve learned how hard-working and smart trees are, you can breathe easy knowing they can withstand the winter… well almost.  There is definitely reason to be concerned when we have an extremely cold winter.  The trees will survive, but they are working overtime to produce those sugars and transform their physiology to prevent freezing.  After harsh winters (like the one it seems we are in for) it is more important than ever to feed and fertilize your trees and shrubs in the spring.  They will absolutely benefit from the added boost of nutrients before they enter their real busy seasons, Spring and Summer.

Call today to schedule a spring fertilization from our certified arborists at Emerals Tree and Shrub Care: (914) 725-0441.



Beware! De-Icing Salt Can Damage Your Plants


It’s that time of year when municipalities, homeowners and local businesses are liberally spreading rock salt on sidewalks, roads and steps to prevent human falls from slippery surfaces. Did you know though, that while this is a great safety precaution to take for humans, it can have severely damaging effects on your landscape’s plants and shrubs? It may take some time for you to notice the effects salt has on your plants, as it will first be absorbed into the soil, and will slowly move to the roots, stems and buds causing permanent decline and even death. Over time, sometimes years, exposure to salt will result in wilted, disfigured foliage, stunted growth and overall bad health.

Because the damage won’t be recognizable until the next growing season, or even for some time after, it’s important to take steps to help avoid salt runoff from reaching your precious greens.

  • When possible, avoid using rock salt all together.  And if it must be used, dilute it with sand or another abrasive.
  • Improve drainage of your soil by adding organic matter such as activated charcoal or gypsum.
  • Build barriers between your plants and nearby sidewalks, roads and walkways that may be subject to de-icing salt runoff.
  • Select salt-resistant trees to plant in areas where salt exposure is inevitable.  Need suggestion, just call us 914-725-0441.
  • Prune properly and add fertilizers to correct nutrient deficiency as indicated in spring soil testing.

If you have plants, shrubs or trees that are showing signs of salt damage and you’d like a professional opinion, please call us today for a free arborist consultation: 914-725-0441.  As always, we are here to help protect your precious greens in every season.