There is a spruce ips beetle infestation in the Denver metro areas. The beetle was found in northeast Denver and has since spread citywide. When the outbreak began, beetles infested older spruce trees, generally on construction sites. With the population of beetles exploding this past summer, all spruce trees are in danger.

The beetles bore into the tree causing a vascular wilt effect. The tree is then unable to transfer water to the upper portion of the tree. Damage includes needles turning rust color to reddish brown starting at the top of the tree. This is followed by needles falling off of the tree.

Trees with roots that have been disturbed or are drought stressed are at higher risk. All spruce require a plant health care management program. This includes mulching the area beneath the tree and regular watering, including winter watering. A preventative spray program in the spring should be included in the tree’s plant health care program. Unfortunately, there is no cure for trees once they are infested. Infested trees need to be removed as soon as possible and the wood needs to be properly disposed of to prevent infestation of other tree

Water your trees! Fall and Winter watering may be one of the most important things a tree-owner can do to help insure tree vigor. Even with small amounts of moisture, Fall and Winter present periods of draught, and your trees need all the help they can get for next spring. Trees lacking water  are more susceptible to branch die-back and stem damage. To help prevent this you should be watering your trees once at least once a month with either a deep root feeder or with a garden hose at the perimeter of branch growth (drip line).

At some point, most trees require fertilization. Because a trees natural environment is the forest, materials such as leaves, other plants, and even animal material, fall and decompose on the forest floor. These materials are recycled and used by the tree as nutrients. When a tree is planted in a landscape setting it is usually deprived of this natural recycling process.

One thing you can do is try to recreate the tree’s natural environment by providing mulch rings.  Most people, however, will not be able to mulch their whole yard! Fertilization is needed by many trees to replace the nutrients they are missing.

Fertilizing

Shade trees, like any other landscape plants, will respond to fertilization. Most shade trees exist in nature without much care, but transplanting trees into urban areas or man-made conditions can create problems. Often these trees will be growing in restricted root zone areas, be surrounded by pavement or compacted soil or even be physically damaged by construction activities. One should realize that the root system is just as important (and delicate) as the above ground parts. 

Fertilizer alone will not improve the health of a tree stressed by one of these environmental conditions. Fertilizer is only one factor in the complex formula of plant requirements.

Here’s how to detect if your tree needs fertilizing. 

Symptoms of a nutrient deficient tree include:

• a slow rate and low amount of annual growth on twigs and trunk, 
• smaller than normal foliage, 
• off-color foliage, 
• increased amounts of dead branches,
• tip-die back in branches,
• and increased rates of disease and insect problems. 

Trees that possess these symptoms generally would respond to a fertilization treatment. One should make sure that nutrients (or lack of) are the problem before fertilizing. Other common tree disorders to be aware of in urban areas would include poor planting techniques, moisture problems, construction damage, girdling roots, or utility leaks from a natural gas line or sewer line.

Homeowners and professional arborists depend on mulch in landscapes for several reasons. Functionally, mulches discourage weeds from growing, conserve moisture during drought periods, and allow better use of water by controlling runoff and increasing water-holding capacity of light, sandy soils. 

Mulches help maintain a uniform soil temperature. A 3- to 4-inch layer of mulch can add to the aesthetic value of a garden while protecting the base of trees from being injured by equipment, such as lawn mowers. 

Mulch rings also decrease competition from lawn grass. Lawn grass, especially when lush, robs trees of valuable nutrients and moisture.

Many organic materials can be used as a mulch. Bark mulches and wood chips are the two most commonly used mulches in most of the country. In the south, pine needles are included in that list.

Mulch can be applied just about any time of the year when trees and shrubs are being planted. The best time, however, to apply mulch in established bed areas would be in mid-spring when the soil temperature has warmed up enough for sufficient root growth. If applied earlier, the mulch will keep the soil temperature lower and root growth could be delayed. 

Mulches should be applied 2 to 3 or 4 inches in depth over relatively clean, weed-free soils. Do not pile mulch more than 4 inches. Identify and eradicate the weeds before the mulch is applied. Keep mulch pulled 12 inches back from the tree trunk.

Most arborists consider organic mulches as the most compatible with trees. There are, however, several inorganic materials used as mulches. These include weed barriers. 

Black plastic is sometimes used to discourage weeds, however it interferes with the normal oxygen and water supply to the tree’s roots. When the plastic is used, a very shallow root system is created and during drought periods the plants may not withstand the stress. It is recommended not to use black plastic around trees. 

There are, however, several landscape fabric “mulches” available that will function the same as plastic, but allow for normal water and oxygen exchange. These materials, sometimes called geotextiles or weed barriers, are placed on bare soil around trees and shrubs with mulches used on top. There are many brands and types of materials from which to choose. They have proven to be beneficial in discouraging weeds and conserving soil moisture