Winter Burn

We are noticing a lot of Winter Burn or Winter Injury to a variety of trees and shrubs.  Winter Burn develops when the weather is unusually warm during the Winter months as it certainly was in February. When it is that warm, trees begin to come out of winter dormancy and their buds start to swell and grow. Then, when the temperatures drop back below freezing in March and early April the buds become dried out and damaged when the leaf tissue re-freezes. The damage can become more pronounced as the Spring progresses. The leaves can look droopy and wilted or have brown edges or ‘dead spots’ in the middle of the leaf as shown in the photo.

It is important to note that this is NOT early stage Apple Scab Fungus, Cedar Apple Rust or Tar Spot. There is nothing that can be done or could have been done to avoid this situation.

LEAVES OR NEEDLES ON CONIFERS OR EVERGREEN TYPE TREES

We are also noticing browning on evergreens such as Hemlock, Juniper, Pine and Yews and broadleaf evergreens such as Rhododendron and Boxwoods. Browning usually occurs from the needle tip on downward. On these types of plants, the damage is attributed to what is referred to as desiccation or water loss due to transpiration. Winter sun and freezing winds dry out needles or leaves that remain on the plant all Winter. The way to minimize this type of damage is to thoroughly water plants that are susceptible to this problem on your property in the late fall up until the time that the ground freezes.

ANTHRACNOSE FUNGUS

The green leaves laying on the ground in the below picture are from an Ash tree that was photographed on May 15th. This is due to a fungal condition called Anthracnose. The wetter the Spring, the greater the possibility of Anthracnose attacking certain trees. We see it most often on Ash, Maple and Sycamore in our area.

On Ash trees, the fungus attacks the stem causing green, seemingly healthy leaves to fall to the ground. An Ash tree can lose up to 75% of its leaves when it is hit with the Anthracnose fungus but the tree will regenerate a second crop of leaves usually in June.

On Maple trees, the leaves curl and wilt and it’s often difficult to tell if the damage is from Anthracnose or Winter Burn.

On Sycamore trees, one of two things typically happen – either the tree leafs out normally and then its leaves fall to the ground like the Ash trees do or the fungus attacks the buds and the tree doesn’t open its initial crop of leaves until mid-June. Quite often, homeowners will think their tree is dead and hire a tree removal company to have it removed. If the tree company is not familiar with Anthracnose, they will remove the tree not realizing it is still alive. If they are unscrupulous, they will be out to remove it quickly before its leaves open. Unfortunately, we have seen this happen before.

Sycamores with this condition will, almost 100% of the time, sport a crop of leaves at the very top of the tree while the rest of the tree will be barren of leaves. If you see healthy green leaves up in the top 2% of the trees canopy, the tree is still alive.

We do not offer treatment to prevent Anthracnose for a variety of reasons but mostly because it is ‘hit or miss’ as to what years it will show up and affect your trees.

As long as you are having Tree Green root feeding your trees, they will be strong enough to survive these conditions.

Have a great Spring!

Trees that retain their leaves all winter

Every year we receive several calls from clients asking why their Oak, Hornbeam or Beech trees retain their dried-out leaves over the winter. These dried out leaves are referred to as ‘marcescent’ leaves. There are varying opinions as to why this occurs.

Here is what happens.  Early cold Fall weather or frost seems to encourage some trees to hold onto their dried-out Fall leaves. For some trees, especially certain Oaks, clients mention that a particular tree seems to experience this every year.

For most trees, cells release enzymes that unglue the leaf from the tree in the Fall allowing them to fall to the ground. But early cold or frost can interfere with the process on these previously mentioned varieties of trees. Marcescent leaves are more common on smaller trees or on the lower branches of larger trees.

Some believe that this process occurs with trees that are lacking proper nutrients. But we at Tree Green do not believe this to be the case. Why? Because we have clients whose trees we have been feeding every year for 20 to 35 years still experience this situation. We know that there is no possibility that these trees are lacking nutrients when you consider the suspension of rich minerals, nutrients and amino acids that our root fertilization process provides.

When the new tree buds form and begin to swell in the Spring, they will push off last seasons dried leaves as you have experienced in the past.  Until that process occurs don’t worry about your tree at all. Just enjoy those rustling brown leaves that seem to be ‘waving’ to us throughout the Winter.

A Rough Spring Ahead?

We’ve recently noticed that certain types of flowering trees and shrubs have their 2016 flower buds swelling, and in a few instances, actually opening this December! Why? The trees are confused.

The abnormally warm November and December is tricking certain Magnolia, Crab Apple and potentially other plants into thinking they should be flowering. We’ve seen this happen before. What may unfortunately occur is this…

When the flower buds are tricked into swelling ahead of schedule, whether they actually open into flowers or not, they may be damaged by the inevitable cold winter which will surely follow. It may not be as cold as usual due to El Nino, but it will be cold enough to burn and dry out the buds. This means that your tree may not flower at all in 2016, or the flowering may be sparse or weak.

We already know that we will be receiving calls next spring where the messages will be as follows….

”You sprayed our tree last year and now it won’t flower”. Rest assured that if this happens to your tree, it has nothing to do with any applications. Mother Nature is the guilty party.

This situation can also occur when we have an unusually warm January or February. Those flower buds swell early, and then if we get night time freezing temperatures in March, ‘Winter Burn‘ sets in and the buds suffer from the same negative effect.

A lot will depend on the exact varieties of trees that are involved within each species, not to mention things like soil moisture as well as directional exposure in relation to your house or other mature plantings, which may or may not protect them from cold winter winds. Only time will tell as to whether or not your trees will be affected next spring.