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Plant Material Issues in This Kind of Winter

by John Rice

I think early January of 2015 was one of the harshest periods for plant material in our part of Massachusetts. The January 5-11 period is a perfect example: low temperatures were 14°, 3°, 1, −5°, 10°, 1°, and 5° with no snow on the ground. With no snow on the ground that cold was able to penetrate deeply into the ground and, therefore, into the plant’s roots, where it could damage or even destroy the roots or the plant. Before that stretch of cold temperatures, it was 48° and 43° on January 4th and early on the 5th; that quick turnaround of temperatures is hard on the conifers and evergreens that don’t really go dormant in winter like the deciduous plants. We have to wonder: how awake were our evergreens when it was 48 out, and did they shut down fast enough with the cold temperatures only hours away? And on top of the temperatures, we also had relentless winds the last two months – first in the storms and then just in the day-to-day, keeping it so much colder than average.

Fluffy snow turned into ice blocks as the temperatures warmed.

Fluffy snow turned into ice blocks as the temperatures slowly warmed after the deep freeze.

An additional challenge for plant material this winter was the snow. Initially with the late January and early February storms, the cold temperatures kept the snow light and fluffy, and though the snow was very deep, it did not weigh a crushing amount when resting on most of our plants. (Boxwoods were one exception.) As the sun got higher and the temperatures warmed the snow, the melting snow went through a transformation from a million independent little flakes sitting on the plant to a block of ice on the bottom followed by layers of snow with the lightest at the top. The snow at the bottom melts from the increased temperatures and the heat generated from the weight of the snow above, freezes at night, and becomes a heavy block of ice that also can freeze right onto the upper leaves and branches of plants. This ice block is very heavy and as a result it 1) splits and breaks branches and 2) crushes the plants interior passages that carry the water (xylem) and nutrients (phloem). The ice on the leaves can also suffocate the leaves, damaging them or even killing them.

Lots of broken branches resulted from the snow loads.

Lots of broken branches resulted from the snow loads.

What You’ll See Now

You can find the results of the harsh weather on your plants:

  • Evergreens have a hard time with this kind of variable weather and can get winter burn: the leaves turn brown or black and die. The whole plant can even die. You can see a brown tinge on needles and leaves or, worse, on entire trees and plants. In addition, I’ve seen lots of conifer needles lying on the snow, the needles literally blown off the branches from the strong winds. With all the strong winds this winter and spring, I expect to see a lot of desiccation problems this spring.
  • Lingering problems from last year’s droughts, especially on hemlocks, rhododendrons, and other shallow-rooted plant material, and especially any plant less than three years old.
  • Wind damage to trees and shrubs from the strong gusts.
  • Salt damage to lawns and plants.
  • Lawns could have plenty of winter fungus in them from all the snow. Also, expect vole damage on your lawn with the deep snow protecting them from the birds. It was 60 degrees around Christmas day and then soon thereafter we went into a deep freeze. December was also wet and in some location as we went into the deep freeze, water on the lawns froze and stayed frozen through the winter. Anoxia and suffocation can happen to our lawns when that happens.

What to Look for This Spring

Moving into spring, watch out for the following issues on your property:

  • Dead trees: If you have had a tree die, have it checked for the Asian Longhorned Beetle (ALB). This is by far the most dangerous pest issue in our area. Everyone needs to keep an eye out for the beetle.

    Everyone should keep an eye out for the Asian Longhorned Beetle, which continues to threaten New England trees.

    Everyone should keep an eye out for the Asian Longhorned Beetle, which continues to threaten New England trees.

  • Damaged tree bark: Bark that has been eaten or rubbed away at the bases of trees or along the branches indicates voles or rabbits.
  • Damaged trees and shrubs: Watch for branches in your trees that are broken off (hangers), cracked, or otherwise damaged. Check trees and shrubs for slits, cracks, or splits on the branches, main stems, or trunk. Check the south sides of woody plants in particular.
  • Dry plants: Especially check on hillsides where the water drains quickly. Look for swelling and budding/leaf breakage and then a slowdown in growth or wilting plants. Also check your most recent plantings and plants that get full sun.
  • Ridges or runways in your lawn or beds indicates vole activity.

What Can You Do for Your Plants and Lawn?

  • Most plants need a great deal of water in the spring, so keep an eye on the moisture and how regular the rain is during the rest of March, April, and May. In particular, water new plantings (planted in 2012-2014) so the plants have water when they need it.
  • Stay off the lawns and beds as much as possible to avoid compaction.
  • Transplant any plants that have heaved out of the ground ASAP.
  • Usually during late March into early April, all the roots on your lawn will die and the grass will start to grow new roots. Avoid raking your lawn during that transformation.
  • Deer will still be eating in our yards until May. The deer in many areas stayed away because of the really deep snow. As that snow melts, expect super hungry deer to be back. Spread/spray deer repellent or use netting so your plants can recover. If deer ate part of your plant, wait until at least Memorial Day before you do any pruning of the eaten part of the plant. Don’t fertilize the plant. Water as necessary.
  • Prune damaged woody plant material.
  • Put down vole repellent in your beds as soon as the snow melts. Rake up vole damage on lawns after the new roots have taken hold.
  • Apply gypsum to salt damaged areas.


    Bag and remove the first lawn clippings of the season to avoid fungus problems later. Photo by Stan Shebs.

  • Have your lawn team pick up the lawn clippings from the first cutting of the year and bag them so the fungus is removed from your lawn. The first cut should be at 2” high. After that, set a height of 3.5”. If the first grass cuttings are not bagged, your lawn is at risk of having fungus problems later in the year.
  • Seed any bare spots in your lawn so you have competition for the crab grass seed that is in the soil too.
  • Fertilize your bulbs and put down vole repellent.

Animals and Insects on Your Property

  • Ticks: I expect some die-off of ticks from the cold and snowless days in January.
  • Woolly adelgid: Check your hemlocks for small white balls on the underside of the needles. Good news! It was cold enough to kill many of them, so infestation is expected to be less than as a result of our warmer winters. If you see any, treat for this with horticultural oil in late April. Do not fertilize infected trees.
  • Winter moths: Biological controls seem to be working in many areas, and we have only pockets of problem areas. Unless your trees/shrubs were completely defoliated last year, I recommend saving your money and not spraying for them.
  • Voles: There will be some vole damage to lawns and voles and rabbits eating the tender bark on young trees, especially Japanese maples.
With snow gone, deer will have easier access to yards.

With snow gone, deer will have easier access to yards.

  • Deer: Browsing activity (with all the snow cover) seemed to be much lighter, so far, than most winters. With the snow now only about 12” deep, I expect deer to be coming out more to eat and to eat a lot. I would love to hear your reports on them. With such deep snow cover, a good 36 inches, it looked like we might have some deer mortality, but given it only lasted six weeks it looks like that did not happen. (Coyotes on the other hand have looked really emaciated this spring) As mentioned above, look out for plants eaten by deer, and be sure to protect against them until May.
  • Coyotes and Foxes: I know people are afraid of them, especially the yipping sounds coyotes make, but we need these hunters to keep the rabbits, voles, chipmunks, and mice populations in check. The populations of these animals are shooting up as we sterilize our ecosystem. Please support these hunters staying in our woodlands and corridors.
  • Lily Leaf beetle: Good news! Soon we can bring the lilies back! We released three bio-controlled agents into the area. Now we just need enough lilies out there so the agents can spread from plantings to plantings.
  • Bee Colony Collapse: Europe has banned or severely limited the use of imidacloprid (Merit) because of studies showing a direct link to the collapse of their bee colonies. Imidacloprid was first used on termites because it caused them forget how to find their way home. That is what is happening to the bees: the bees get the chemical from the flowers they are pollinating and don’t go home. Imidacloprid is one of the top chemicals used in the US today; there are no restrictions on it at this time. It is used in lawns to treat grubs and on trees and shrubs for just about every pest problem. Avoiding products that contain imidacloprid and other neonicitinoids helps not just the bees, but butterflies and other pollinators. You can find a list of products containing these chemicals on the Xerces Society website.
Provide habitat for threatened Monarch butterflies by planting milkweed.

Provide habitat for threatened Monarch butterflies by planting milkweed.

  • Monarch Butterfly: Monarchs have experienced a 75 percent decline in the last two years. Black swallowwort (an invasive weed) is fooling the butterfly into thinking the black swallowwort is milkweed or butterfly weed which are the only two plants that can help the butterfly. The butterfly lays its eggs on the black swallowwort and, because it is toxic, the larvae die. So be on the lookout for black swallowwort and weed it out. Imidacloprid may be also involved in the monarchs decline. How can you help? Plant butterfly weed and or milkweed along your sunny borders or corridors (boundary areas).
  • Salamanders: Earthworms, so good to have in our gardens, have invaded our forests, eating the leaves and the forest duff at such a high rate that the food the salamander babies need for just a few weeks is no longer available in the leaf litter. The result is increased mortality rate for the newborns. We think this is happening to other amphibians, too.
  • Worms: As stated above, worms have invaded our forests eating the leaf litter at a very high rate and therefore leaving tons of casting fertilizing our forests. Sounds like a good thing, right? No. Our New England forests are fungi based, and the worms are changing it to be it bacteria based soil. In addition, the castings the worms are leaving actually help to suppress the germination of the native trees seed by burying them too deep to germinate. What can you do? Control the invasives on your property and support your town doing the same on its (our) property.
  • Spotted wing drosophila: Major pest. If you have blueberries, raspberries or strawberries, pick them a little early and put in the frig right away. Buy the early fruiting varieties.

Invasive Weeds Report

  • Japanese Knotweed: A release of a psyllid bio-control agent has been approved; expect it to be released next year.
  • Mile-a-minute: Weevils were released and initial reports on control are promising.
  • Black Swallowwort: A bio-control has been released in Canada and is expected to be released in US by 2016. Will it be in time to save the monarch butterfly?
  • Garlic Mustard: Many problems attributed to GM are actually caused by deer. Bio-control pending review. GM is toxic to some of our native butterflies.
  • Purple loosestrife: Controlled, which is good news for our turtles.

Changes to Lawn Fertilization Programs

  • The excess nitrogen and phosphorous coming off our lawns when we irrigate or when it rains is increasingly a problem for our towns. All synthetic fertilizers are water-soluble so they leach out into storm water run-off and/or the water table. Towns are mandated to clean up that polluted water and the algae-filled ponds, lakes, rivers, etc. the extra nutrients cause.
  • Massachusetts has become the 13th state to pass a law restricting nitrogen and phosphorous use by professionals. As of now our legislature has passed the law, but the new governor has not signed the law; it is unclear if he will. If you hire an outside contractor to fertilize, make sure they are using the new guidelines. This new law is about keeping our drinking water safe as well as reducing pollution clean-up costs. What else can you do? You can call or write the governor’s office and ask him to sign this bill.
  • Guys, don’t panic, you can still have green lawns. We just have been using too much nitrogen and phosphorous. There are water insoluble fertilizers that don’t run off, providing nutrients for the roots as they are needed.
  • Crab grass. Consider seeding your bare spots now so you have a nice lawn rather than spending the money every year on crab grass preemergence killer and post emergence killers. Neither pre- nor post crab grass killers promote healthy lawns. Instead, they weaken your lawn and encouraging more crab grass in your lawn. It’s a perfect catch 22. In only three to five cycles of overseeding, you can thicken up your lawn and crowd out the crab grass.

Overall, we’ve had two challenging months of weather here in Massachusetts. However, while we set record cold in February, many western states, including Yellowstone National Park, set record high temperatures for February. I am grateful that we are getting precipitation at the rate we are. When you consider the drought California is going through now, year after year, its implications are sobering. Many scientists are saying this is not a drought, but rather the new normal. We need to build strong landscapes for whatever the future holds.

About the Author

John Rice owns Inspirational Gardens, an organic and ecologically based landscaping company located in Acton, MA. John may be reached at