Protecting Broad-leaved Evergreens for Winter: Anti-Desiccant Spray

Broad-leaved Evergreens

The temperatures are dropping rapidly here in the northeast and it is time to apply anti-desiccant spray to your broad-leaved evergreens to protect them from winter damage.

What is desiccation?:   Certain broad-leaved evergreens are susceptible to winter burn and drying from harsh winter winds here on Long Island and anywhere where winter temperatures drop below freezing. Desiccation, or extreme drying is caused by moisture loss from the leaves by transpiration. A precautionary measure for this drying is the use of an anti-desiccant, which can help to prevent damage to your landscape plants.  Anti-desiccant spray is an organic based spray application that lasts for approximately three months throughout the winter, and helps to prevent water loss from your evergreens.

Which plants should be sprayed with an anti-desiccant?: Apply an anti-desiccant spray to your broad-leaved evergreens such as holly, rhododendron, cherry laurel, skip laurel, mountain laurel, Japanese skimmia, leucothoe, aucuba and boxwood when the daytime temperatures start falling below 50 degrees (around Thanksgiving here in zone 7 Long Island). Apply when the temperatures are above freezing and there is no threat of rain or frost within 24 hours. (This tip applies to areas going into their winter season-temperatures dropping below freezing: 0 degrees Celsius or 32 degrees Fahrenheit.)

When to Apply: Apply anti-desiccant when the daytime temperatures start falling below 50 degrees (late fall/early winter). Apply when the temperatures are above freezing and there is no threat of rain or frost within 24 hours.

Dangers: Be sure to read all directions on the label since anti-desiccants can cause photo toxicity on some narrow needled evergreens such as Arborvitae and Spruce that could cause more harm than winter burn.  Spraying in freezing temperatures will do harm to the plant.  Do not spray in freezing temperatures and allow time to dry before temperatures drop below 32oF or 0oC.

How often should I apply anti-desiccant?:  Sudden warm spells can trigger your evergreens to open their pores allowing for more water loss. If there is a winter thaw part way through the season it is recommended to re-spray your plants but only if the temperatures are to remain above freezing for at least 24 hours.

Where do I purchase anti-desiccant?:  The most commonly used brands of anti-desiccant are Wilt-Pruf, Vapor Guard and Transfilm that can be found in nurseries and garden centers. There is a new brand of anti-desiccant on the market which requires only one application. Ask your landscape professional for more information.

Informational Links:
A Guide to Northeastern Gardening on Facebook
Landscape Design by Lee on Facebook

NEGardening on Twitter

My Published Book: A Guide to Northeastern Gardening: Journeys of a Garden Designer on Amazon

Author:  Lee@Landscape Design By Lee 2016. All Rights Reserved.page-divider-autumn

Got Snow? – Winter Garden Maintenance

snow 2014

Snow Covered Weeping Blue Atlas Cedar

While winter is here and I look out at my evergreens buried under a blanket of snow, it is a good time to review some basic maintenance tips to prevent possible damage to your landscape plants.

SNOW REMOVAL:  While it is tempting to go outside and start removing snow from weighted branches it is also a good time to exercise caution.  Under the snow-covered branches could also be a frozen layer of ice.  Any manipulating of the frozen branches could result in easy breakage and permanent damage to your tree.  A helpful tip is to very carefully dig snow from around trapped branches and allow them to spring back up on their own. Never shake branches with ice.  It is best to let nature take its course and allow thawing to occur.  The branches will gradually regain their shape as the ice melts preventing any harm to your landscaping.

BROWNING OF EVERGREENS: You may be noticing browning on some of your evergreen trees. Browning in the center is perfectly normal and is how a tree sheds old needles to allow for new growth in spring.  Needle shedding usually happens in the fall but is frequently much more noticeable once the snow arrives.  Browning anywhere else on the tree such as on a leader or outside branches can be cause for concern.  If an entire branch turns brown it could be that the branch is broken and should be removed when the weather allows to avoid stress and disease to the plant. Browning could also be the result of “winter burn” which I will discuss below.

WINTER BURN:   Winter burn is the drying effect of winter winds which can cause evergreens to appear brown. I have been getting a lot of questions this winter season regarding winter burn on evergreens such as Arborvitae, weeping and upright Blue Atlas Cedar, Cryptomeria and Golden Oriental Spruce.  The narrow needles/foliage on these evergreens are even more susceptible to this effect.  The abundant snow and reflection of rays from the sun also serves to magnify this phenomenon.  This browning of the needles or “winter burn” should correct itself once the weather starts to warm and water is able to get to the cells of the plant and once again activate the chlorophyll within.  If the tree is well established it should most likely fully recover and start to push out new growth as the temperatures rise. As an extra note, your broad-leaved evergreens such as rhododendron, cherry and skip laurel, boxwood and holly (to mention a few) should be sprayed with an anti-desiccant spray before winter arrives.  See Anti-Desiccant on Broad-leaved Evergreens in November for more information.

Stay warm…winter is almost over.

As Always…Happy Gardening!

Author:  Lee@Landscape Design By Lee, 2014, All Rights Reserved

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Winter Burn on Eastern White Pine

Pinus strobus (Eastern White Pine)

Pinus strobus (Eastern White Pine)

Hurricane Sandy caused damage to many evergreen trees here on Long Island and along the eastern coastline. The Eastern White Pines seemed to be most affected by the high winds and salt spray off the ocean and are showing signs of decline now in the month of December.High winds cause excessive transpiration (water loss) from needles of the pine causing them to turn reddish-brown, giving the tree a dead appearance.

There could be hope for the tree before it is taken as a lost cause.  Search for evidence of green viable buds.  If you see any green within the needles (see below) then the tree has a chance of bouncing back in the spring providing the winter isn’t too harsh. As water gets to the roots and needles of the tree there is a good chance that new growth will start to emerge.   Deep root feeding your damaged pines in late March (early spring) can also help to promote new growth.

pine damage

Winter Burn on White Pine

Pines naturally shed their older needles once a year usually in Fall or Spring and go through a major shed every three years.

For your damaged pine it could take up to three years for the tree to fully recover as it drops old needles and replaces with new but the tree could eventually make a full recovery.

Author:  Lee@Landscape Design By Lee, 2012, All Rights Reserved

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