WINTER INJURY

We are seeing a number of different types of trees and shrubs that have apparently suffered damage or died over the Winter. It seems that the most affected are those shrubs that retain their leaves over the winter such as Boxwoods, Euonymus, Holly, Azaleas and Rhododendron. But some plants seem to have just up and died. Japanese Maples seem to be particularly hard hit as well.

boxwood winter injuryThe Boxwoods shown in the photo are an ‘extreme’ example. These shrubs should be fairly dark green in color. The red arrow points to the color these shrubs should be. These Boxwoods will not recover and will need to be removed and replaced.

While any winter can be stressful to certain trees and shrubs, this past winter was particularly devastating with its 30 to 60° below zero wind chills. This is why we tell folks to water trees and shrubs going into December if we experience a dry Fall. It is important to fully hydrate plants prior to ground freeze to limit possible damage.  At the very least, we recommend not planting Boxwoods. They seem to suffer damage far more frequently than any other plant.

Note…Any time you see winter damage on plants, don’t be hasty and remove them. Hand snipping will remove whatever browning exists and then wait to see what new growth appears in Spring and early Summer. If the damage is minor and the plant is still aesthetically pleasing to you, you won’t need to remove it.

On a separate note, we are also telling folks to avoid planting any Spruce trees because of the growing Rhizosphaera Needle Cast situation which we mentioned several times last season. If you need evergreen or pine type recommendations, we suggest planting Hemlocks and White Pine in more shady areas and Concolor Fir, Vanderwolf and/or White Fir in more sunny areas. Avoid Blue Spruce or Colorado Green Spruce.

Viburnum Leaf Beetle

Be on the lookout for the Viburnum Leaf Beetle, an extremely destructive pest. Pictured above are two rows of Viburnum at different stages of damage, one half eaten and the other completely defoliated!

We all love Viburnum for their sweet smell and their beautiful floral display in the Spring but unfortunately the Viburnum Leaf Beetle seems to love them even more.

Shown above is a single Viburnum leaf with 18 of the immature beetle larva feeding on it. The larva can range in color from yellowish green to a light/medium brown. Imagine how many must have been present in the photo of the completely defoliated Viburnum shown above.

This destructive Beetle loves certain varieties of Viburnum more than others but IF THEIR FAVORITE VARIETIES ARE LEFT UNTREATED FOR 2-3 YEARS, THEY WILL KILL THOSE PLANTS!

These insects emerge in May, retreat into the ground in mid to late June to pupate for 7 to 10 days and then re-emerge in July as adult beetles. At that point they resume feeding until Fall.

Tree Green’s treatment program consists of two to three well timed insecticide spray applications with quality insecticides. In addition, we rotate insecticide choices as insects will develop a tolerance and resistance to repeated use of the same products. Insect and fungus control can be quite complicated.

Just today, we heard from a client who saw the damage starting this past weekend and tried to treat himself with insecticidal soap. I’m sure he won’t mind us relaying his story to help protect and warn others. He got the product in his eyes and had to go to the hospital emergency room. If you only have a single bush that you want to try to treat yourself – be very careful. In their pure form, these products burn skin and eyes and put off vapors that shouldn’t be inhaled.

There are several varieties of Viburnum and we realize many of you may not know whether you have Viburnum or not so we recommend the following:

Keep an eye on your shrubs! If you see bushes that are thinning or browning, look at the damaged leaves and compare them to the photo shown earlier with the little critters all over it. If you see similar damage, call us! We can stop them in their tracks this year and more importantly, prevent their damage next year and beyond.

For the record, this is what a healthy, free-standing Viburnum looks like. It is a spectacular plant, so keep a wary eye!

Crab Apple Trees Flowering in November?

You may have noticed that certain varieties of Crab Apple trees are displaying some  minor flowering right now. The below photo was taken October 31st.

The months of September and October were abnormally warm. This warm weather will confuse many flowering trees and shrubs.

Flower buds for the following year always form during the prior season. Ordinarily these buds sit closed on the tree throughout the Fall and Winter waiting on Spring. However, if the Fall season is unseasonably warm and those buds receive above average warmth for an extended period of time, a second flowering can occur.

What this means is that these trees will not flower as fully next Spring and in some rare cases, may not flower at all depending on the variety of tree involved. Even though you may not be seeing this second flowering occurring on your tree at the present time, that does not mean that your tree might not be affected next year.

Even if flower buds fail to open as those shown in the photo, they may have swelled beyond the point that they normally would. If that is the case, it is possible that Winter’s cold temperatures and winds might burn the swollen buds that are not as dense, compact and insulated as they normally would be. Should this occur, the buds will sustain damage and not open next Spring. Only time will tell.

On a better note, we have been driving past clients homes this Fall checking on our fungal treated Crab Apple trees and we hope you are as happy with their condition as we are. We promised our new treatment products for 2017 would produce tremendous results and they obviously have! We are seeing Crabs that are still fully leafed!

Have a wonderful Fall and upcoming Holiday Season.