Late Winter Bronzing of Evergreens-Is it Normal?

Late Winter Bronzing on Evergreens

What is “winter bronzing”? While approaching the end of winter, some of your favorite evergreens may appear to take on a bronze appearance. You may be wondering. “Is this normal or is my plant dying?” Changing foliage color is a normal phenomena that affects some evergreens near the end of winter while seasons are transitioning. Freezing temperatures, followed by a warming trend, longer hours of sunlight, then more cold can trigger foliage to discolor. The color change is a reaction to low temperatures, winds and sunlight, causing mild desiccation of the needles or leaves, allowing the underlying colors to show through. This dulling of green foliage is more pronounced on plants that receive more sunlight. The result is commonly known as “winter bronzing”. The longer the ground is frozen and the more water that is evaporated from the plant than it can take in, the more pronounced the foliage will appear to turn from green to brown, bronze, or even orange or purple. This process is similar to why deciduous leaves change color in the fall. While the tree is going dormant for the winter months, chlorophyll production subsides and the true underlying colors of the leaves are revealed.  When can I expect my trees to look more normal? Once the temperatures rise and new growth is stimulated, the foliage will turn back to a more vibrant green. Broken or dead branches are different in that they are completely dried out and brown. Those branches should be pruned off the tree in late winter/early springtime to prevent any further damage. Any falling or divided tree leads can be arbor tied to secure them and encourage upright growth. Split branches can also be arbor tied together, and if caught in time the cambium growing layer of the tree can mend. In the photograph above, the center upright Western Arborvitae are displaying signs of bronzing with no evidence of  any completely browned or broken branches, both indications of a normal and healthy tree.

For more gardening tips and design ideas: My books on Amazon:

A Guide to Northeastern Gardening: Journeys of a Garden Designer Zones 3-9
Landscape Design Combinations

Author:  Lee@Landscape Design By Lee 2018. All Rights Reserved.

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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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The Insulating Effects of Snow

Snow InsulationYou may have heard that snow is a good insulator for your landscape plants.  Well indeed it is!  A blanket of snow is composed of approximately ninety percent trapped air and ten percent water.  Snow serves the purpose of providing a protective barrier (insulation) separating plants from the lower temperatures around them.   Stored heat in the ground being radiated is trapped under the layer of snow; hence, maintaining plants at a slightly higher temperature than the surrounding environment. This creates the same effect as the insulation barrier in the walls of your home.   Mulch is also used as an insulating barrier for plants and the snow helps to further maintain the temperature of the soil.

Even when temperatures plummet the temperature under the snow will stay fairly constant around 32 degrees helping to protect underground roots from winter damage.   Besides forming a protective barrier, melting snow also provides a source of water for plants during the cold winter months.  With the frigid temperatures we have been experiencing it is good news that snow cover can be beneficial for your landscape and is nature’s natural insulator!

As Always…Happy Gardening!

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

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Long Island Blizzard Tree Care Tip

snow on branches

Well we finally got that snow we’ve been lacking and a lot of it!  We officially got 19.8 inches of snow here on parts of the south shore and more elsewhere on the Island.  If you have ventured out you will notice tree limbs drooping due to being over weighted with snow and the first reaction is to brush them off… but beware.

For the best care of your trees with snow-covered branches first allow the sun to start melting the snow and the branches will gradually start to pop back up.   If you are able to gently brush off the snow do so but if the snow is frozen on the branches let it melt naturally in order to avoid tree breakage.   The tree branches are very fragile right now and can be damaged easily.

Stay warm.  Spring is on its way!

Author:  Lee@Landscape Design By Lee, 2013, All Rights Reserved

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February Garden Maintenance Tips

Winter Garden

February Gardening Tips

As we head into the second half of winter in zone 7 there are a number of outdoor tasks that can be performed in order to ensure the health and vitality of your landscape plants.

Frost Heaving:  A usual occurrence in winter is frost heaving.   Soil around your perennials freezes and thaws causing your plants to heave up out of the ground.  This causes the plant to dry out and become more exposed to the cold, usually leading to the demise of the perennial.  An easy remedy is to lightly step on the soil around the plant and add a thin layer of mulch to protect it the roots. 

Winter Pruning:  Prune ornamental flowering and fruit bearing trees in need of shaping while they are still dormant.   Generally, trees that flower after June set their buds in spring and can be pruned while dormant.  Early spring-flowering trees set their buds in winter and should be pruned after flowering.  In cases where the tree is in desperate need of pruning it is more beneficial to lose a few blooms and prune when the branch structure of the tree is visible and easier to see.  Prune out any damaged or crossing branches that could cause injury and jeopardize the health of your tree.  Additionally, it is good for the aesthetics, structure and continued flowering of  your ornamental trees to give them a good shaping on a regular basis.  This task can also be performed in the late winter.

Winter Drying (Desiccation):  Check your evergreens for signs of winter drying.  If a period of warming and thawing has occurred in mid winter it may be time to apply a second round of anti-desiccant to your broadleaf evergreens such as Holly, Rhododendron, Acuba, Cherry and Skip Laurel, Boxwood and Euonymus.  Perform this procedure only if the temperature is going to be above freezing for 24 hours.

As March and April approach there will be more tips on maintaining the garden.  For now performing these simple mid-winter procedures will help to ensure the success of your landscape plants.

Author:  Lee@Landscape Design By Lee, 2013, All Rights Reserved

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