Thoughts on tree care in Douglas County.
Use Mulch and keep those roots moist!
Trees of all types need the proper environment year round for their roots. The biggest problem trees face here is usually allowing the root system to dry out. This can lead to root loss and dying back of the canopy(or crown), or even a loss of the tree itself. To combat this problem the single most important solution is applying a mulch layer under the tree, to the drip line, and about 3"-4" deep. This will help hold moisture during the winter months, and help keep lawn mowers and trimmers away from the base of the tree during the summer. Giving your trees a good drink of water during the fall, and then following with winter watering during dry spells, especially for newly planted and nonnative species is also very important. Watering during warm weather, either with a root feeder or simply by running a hose to the base of the tree and allowing it to "dribble" out at a slow rate for a 1/2 hour or so will help immensely. Remember, 90% of most tree problems start at the roots; keeping them healthy over the winter will go a long ways towards ensuring their health next season.
Winter Pruning
Winter is a great time for pruning, and offers several advantages to pruning during the growing season. Removing wood, weak or diseased branches, as well as proper thinning can help alleviate damage from heavy snow and ice loads.
Another important advantage to winter pruning is that the insects which are attracted to the smells associated with freshly cut wood are dormant. These include the woodboring insects such as mountain pine and ips beetles, two common borers which attack our native pines. Flowering trees such as hawthorne, crabapples and other fruiting trees should be pruned before they flower to reduce the risk of infection from Fire Blight.
A note on tree fertilizing
We all enjoy healthy looking, rapidly growing trees in our landscape. Unfortunately, it can be easy to succumb to the desire to fertilize heavily during the growing season to get this "look". Trees which have been over fertilized and put out too much growth too soon are very susceptible to snow damage. Resist the urge to promote fast growth thru fertilizing. Our native pines, especially, should need little or no fertilizer to grow strong and healthy.
In case of storm damage
With moderate storm damage, restoring the tree to its former health and beauty may take some time, but it generally can make a full recovery. Broken, hazardous branches should be removed as soon as possible. Pruning to remove broken stubs and restore the balance of the crown can be put off a little while, but shouldn´t be delayed more than one growing season.
PINE BEETLES
I read with great interest a published article on Pine Beetles the other day. Being in the tree business as I am, I have dealt with this subject a lot over the years. I have seen the panic in homeowner´s eyes and I have watched as others in the industry take advantage of this panic to sell services that might not be needed. I thought I would add this information hoping that it might be of help to some of you.
There are two types of beetles that attack and kill our Ponderosa pine trees; the Mountain Pine beetle and the closely related Ips beetle. Both are small, approximately 1/4" - 3/8" long. Both bore into a tree and lay their eggs in the cambium layer, right under the bark. It is the larvae eating the cambium, and the blue stain fungus they carry with them, that upset the tree´s uptake of nutrients and cause the tree to die. Their main difference is in their life cycle and which trees they will typically attack, and how.
Mountain pine beetles have a yearly life cycle. They need a bigger tree to attack and will typically infest older, more mature pines that are declining in health with a trunk diameter of 8" or more. Ips beetles have a much faster paced life, and may turn over several generations in a single year. They will typically attack smaller trees under stress, as well as individual branches of larger trees. They are also far more common in Douglas County at the moment.
OK, enough boring facts about bugs. Why do they attack our trees and what do we do about it? Well, first let´s try to understand why they are attacking trees; there are a lot of stressed out trees out there! What is stressing them out?, The drought of recent years has been tough, especially on trees growing in poor soil on south facing slopes. The snow storms that broke branches off trees everywhere a few years back turned our forests into smorgasbords for Ips beetles; green broken branches everywhere! Add in mild, dry winters and you have text book conditions.
Another huge cause is all the construction going on in forested parts of the county. Trees are pushed over and left in piles, becoming breeding grounds for Ips beetles. Builders try to save trees without understanding the most important thing is to protect the root systems of each tree. Equipment drives around them, occasionally banging into the trees. Trucks are parked under them for shade. The soil gets severely compacted. Then the landscaper comes in and changes the grade, or trenches are dug for utilities and sprinkler lines, cutting roots.
The end result is the unsuspecting homeowner getting a nice new home with some beautiful trees, which mysteriously start dying. All the sudden he (or she) is paying good money to get those trees removed. I see it all the time. Ninety percent of all tree problems start at the root level.
Also going on out there is a lot of trees dying along roadways, and their deaths being blamed on beetles. In many cases what is causing them to decline is the magnesium chloride put down on the roads during icy conditions is raising the salt levels in the soil to the point where the trees cannot uptake nutrients. Reuse water on golf courses, especially in Castle Pines, is doing the same thing. Beetles come in and finish them off and are blamed as the problem, when actually they are more of a symptom than a cause.
So what can you do? If you live in a house that has been built in the last few years, realize that your pine trees may have been impacted in a negative way. Consider calling a reputable company to inspect and spray your trees with insecticide to protect them from attack as they recover from the building stress. Do you need to spray all of your trees? No! Our forests have survived thousand of years just fine without us, and a healthy pine tree can withstand all but the most serious infestations.
If you have large, mature pines that are a valuable part of your landscape, consider having them inspected and sprayed if necassary. If you have newly planted pines, definitely make sure they get sprayed for the next two or three years. Spraying should be done in early spring before the beetles really get flying around.
I am not a big fan of fertilizing our pines. Seems to me that our yearning for rich succulent growth in the summer leads to broken branches from snow loads during the winter. Give them an extra drink of water once a week when it gets dry out there and that will help a lot. Don't over water or turn your sprinklers on them thinking more is better, however. I see a lot of problems due to over watering. A little is good, a lot can be deadly.
Trees are complex, living things. Sometimes they die. That doesn´t help if the one dying happens to be the centerpiece of your landscape, though! Keep an eye on your pines and if you have concerns get them looked at by a reputable professional. And remember, often what is going on above you is directly related to what is going on below you!
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