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.

Yellowing Evergreens

yellowing needles on Scotch Austrian pinesBeginning in August of every year and continuing into the Fall, we’ll get calls from concerned clients that their evergreens trees are yellowing or browning. Many think their trees are dying.

Interior Yellowing of Evergreens or Pines is a common and normal occurrence. This happens to the innermost needles closest to the trunk or base of the limbs. As long as the outer portions of the trees are green, the trees are fine. If entire limbs are dying all the way out and into this year’s growth, then it’s a different story.

For more information on what’s happening, check out our blog post from last fall.

Before and After Tree Treatment

We wanted to share some photos of before and after treatment.  We think you’ll agree they’re pretty remarkable. In the first two photos you see an absolutely enormous Ash tree. This tree is probably 200 years old, or older, with a trunk diameter just short of five feet across. It hangs over and shades the entire back of our customer’s house and stretches out over the back yard. The tree is spectacular and adds tremendous value to the property.

In 2013, we were contaash tree before eab treatmentcted by the owner of this tree, concerned about its obviously weakened condition from the Emerald Ash Borer, as shown in the first photo. You can see by looking at the trees in the background of the first photo, that this tree should have been fully foliated when this photo was taken, as those other trees were.

We gave this potential client a 30% chance, maybe less, of saving this tree but this tree owner said if there is any chance at all, he wanted to try.

ash tree after eab treatment

After 4 years of treatment, you can see how it looks today in the second photo.

Needless to say our client, and we, are thrilled over the result.


To date, we have saved over 94% of the Ash trees that we have set out to save. The only exceptions are trees where treatment was started later than would have been optimal or where there are horrible soil conditions such as too much clay or too wet of an area. These other stress factors, coupled with the constant onslaught that these trees are under from the Ash Borer, were just too much for those trees to overcome.


magnolia tree before treatment

magnolia tree after treatmentIn the second set of photos is a Magnolia tree. The first photo shows the tree in a very weakened, yellowing state. Yellow leaves occur when a tree is lacking necessary nutrients to keep its leaves green. This yellowing can be caused by insects sucking the nutrients out of the tree and/or poor soil conditions. Yellowing leaves are an indication that the tree only has a few years left to live if left ‘untreated’.

In the case of this tree both Magnolia Scale insects, as well as a small plot of soil in which to grow (sandwiched between the house foundation and a driveway), were the cause of its trouble back in 2011. In the second photo you can see the tree today, after six years of treatment. It is obviously thriving and its natural green color is back – thanks to a tremendous reduction in the scale insect problem and proper Root Fertilization.

Now, of the hundreds of Magnolia trees that we treat, we have a few trees in certain neighborhoods that are not responding as well to our treatments against the Magnolia Scale which is plaguing these trees all over our area. Scale insects, whether it is Magnolia, Lecanium, Cottony Maple or Euonymus Scale, are difficult to control. It often takes a few years to get the problem under satisfactory control. Why is this? Because Scale insects are masters at developing resistance to pesticides. The problem is that we don’t know which products they have learned to resist until we see the result the following year. Once we see that resistance might be an issue, we have to switch to different products to get control. Going forward, starting with treatments this coming Fall for this problem, we plan on rotating pesticides much more frequently.