Browning and Needle Shed on Evergreens in the fall: A Natural Process

Needle Shed in Evergreen in Fall

          (Photo Left New Growth)                                      (Photo Right fall needle shedding)

If your evergreen’s inner needles are suddenly turning from a healthy looking green to shades of yellow, orange and brownish-red in late summer and fall there is little need for concern…it is all part of a natural process. Each year evergreens will produce new foliage in spring and they prepare by shedding their older foliage in the previous late summer and fall. Shedding of needles and foliage is a natural process that evergreens go through as a way of preparing for new growth once the weather warms.  As the days become shorter and temperatures lower evergreens go through a slight dormant period similar to deciduous trees and shrubs. Many evergreens such as pine, cedar, Chamaecyparis (Hinoki Cypress), Thuja (Arborvitae), fir, hemlock and spruce lose some of their needles every year and may go through a major shedding every three to five years.

fall foliage shed on evergreens

Fall Needle Shed on Hinoki Cypress and White Pine in late September-November-Shedding can be light or more pronounced. Lightly shaking the branches can help along the natural cleaning process.

To examine, look at your tree carefully.  Older foliage is shed first so the losses should generally be from the inside out and not at the tips.  Prior to shedding the needles appear from green to yellow, orange and eventually brown, remaining on the tree until the process is complete.  The actual amount of needle shed on the tree or shrub varies depending on the growing season, temperature changes and amount of rainfall, and can sometimes be sudden.  Often the change is unnoticeable but generally the drier the season or more drastic the temperature change the more noticeable the needle shed, a natural cleaning process leading to new growth in the spring.

needle shed fall

 Fall Needle Shed on Evergreens Showing Previous Year’s Growth.  Older Growth is closer towards trunk.

Other species of evergreens in the broadleaf category can also shed their leaves.  Evergreens such as holly and laurel retain their leaves for only one year and rhododendron and azalea for one to two years.  Leaves will appear yellow before falling but at some times may go unnoticed if new leaves conceal old foliage.  This process usually occurs in spring when new growth is appearing but can happen at other times of the year as well.  If the whole tree or entire sections of your conifer are turning brown then there is cause for concern and you should have a certified arborist or landscape professional examine it.  Otherwise, fall yellowing or browning at the base or inner branches closer to the trunk seldom indicates a serious problem, but is more often part of the natural life cycle of the tree.

needle shed

Conifer Annual Needle Shed

 For more information visit the following horticultural link:  Cornell Cooperative Extension

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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Repost: Anti-Desiccant Spray on Broadleaf Evergreens In November

The temperatures are dropping rapidy here in the northeast and it is time to apply anti-desiccant spray to your broadleaf evergreens to proect them over the winter.  It is actually too cold today to apply.  Wait until the temperatures are going to remain above freeezing. (Read Below)

Anti-Desiccant Spray:  Certain broadleaf evergreens are susceptible to winter burn and drying from harsh winter winds here on Long Island.  Drying is caused by moisture loss from the leaves by transpiration and the spraying of an anti-desiccant can help to prevent damage to your landscape plants.  Anti-desiccant spray is organic based and lasts for approximately three months throughout the winter and helps to prevent water loss from your evergreens.  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 mid-November 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.)

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.

If there is a prolonged thaw in mid-winter it may be time to re-apply anti-desiccant spray to your broad-leaved evergreens, especially if there are more prolonged freezing temperatures on the way.  Following this simple procedure can prolong the lifetime and vitality of your landscape plants.

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

Dormant Oil: October Landscape Maintenance

garden tips
DORMANT OIL APPLICATION:
Welcome to Fall!  It’s time to spray your trees with dormant oil.  Dormant oil protects your ornamental trees, shade and fruit trees by placing a protective coating on the surface smoothering out any insect larvae that can hatch in the spring and do damage to your plants. Dormant oil is an important tool to manage certain pest problems such as scales, aphids, whiteflies, caterpillars and mites during the winter while your plants are dormant.

 

WHEN TO APPLY:
Spraying of dormant oil should occur on a clear day when the temperatures are expected to remain over 50 degrees F. for at least twenty-four hours. The ideal temperatures for application is between 40 and 70 degrees F.

 

WHAT INSECTS ARE CONTROLLED BY OIL?
Aphids
Tent Caterpillars
Scale
Spider Mites
Leafhoppers
Whiteflies
Mealy Bugs

 

PRECAUTIONS:
Always read directions before application.  Avoid using on plants that are oil-sensitive.

 

SOME PLANTS KNOWN TO BE OIL SENSITIVE:  (Read Directions on Bottle)
Cryptomeria
Junipers
Weeping Japanese Maple
Eastern Redbud
Dwarf Alberta Spruce
Black Walnut
Douglas Fir
Hickories
Smoke Tree

 

Having a regular spray program with proper care of your plants will increase the long-term health and vitality of your landscape and possibly eliminate any major damage due to invasive insects.  Happy Gardening!

 

Author: Lee@Landscape Design By Lee, 2013, 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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Preventing Tree Damage from Snow & Ice

WinterAs winter progresses there is an increased threat of snow and ice build up on the branches of trees and shrubs in the landscape. If snow piles up on your evergreens try to carefully brush it away as soon as possible before freezing to remove the excess weight from the branches. If the snow does not remove easily do not shake the branches. This can cause breakage and damage. If the tree or shrub is covered with ice permit nature to take its course and allow the ice to melt naturally. If your landscape does suffer any damage from winter storms it is recommended to remove any broken limbs to avoid stress and disease to the plant. This can be done when the weather allows.  Preventive measures that can be taken to avoid winter ice damage include keeping your trees properly pruned throughout the year.  Fast growing trees and trees with horizontal branching such as ‘Bradford’ Pear are more prone to damage from excess weight.   Prune away any weakened or overweight branches in fall before snow arrives.

Frost Heaving: In freezing temperatures soil around your plants may be subject to frost heaving. This is when ice forms underneath the soil and expands upwards from the ground causing plants such as perennials to push upwards exposing the crown. Heuchera (Coral Bells) and Liriope are especially prone to this type of damage. As a preventive measure apply mulch finishing to your garden beds. To remedy, slightly tap the soil back down, and brush the mulch back around the exposed crown of the plant to protect it. Following these few simple steps will help to prevent any unwanted winter damage to your landscape plantings.

Author:  Lee@Landscape Design By Lee, 2013, 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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