From Fall 2011 What's New

Every fall Earth-Wise receives phone calls by customers concerned about the browning of needles on their pine, spruce and fir trees. Not to worry, this is a normal process. Depending on species, location and overall health of the tree, conifers typically hold on to needles for 3-7 years. Older needles become less efficient at photosynthesis due to shading from new growth and excess wax buildup. Thus, these older needles are no longer productive for the tree and are shed in the fall.

Excerpts from Spring 2011 Earth-Wise Newsletter

Marssonina Blight May Have You Seeing Spots

Marssonina blight (Marssonina populi) is a fungal pathogen that is native to aspen forests of the Rocky Mountain region. Marssonina is always present to one degree or another, but incidents of the disease are usually more common in years with wet spring weather. The damage to host trees is mostly aesthetic, consisting of dark brown blotches on the leaves and premature leaf drop. However, if a tree is badly infected several years in a row, it may become more susceptible to secondary insects and diseases that pose a more serious health threat. An important step in preventing Marssonina infection is improving cultural conditions. Because the fungus overwinters in previously infected leaf debris, it is important to thoroughly rake up leaves and remove them from your property. Reducing humidity levels in aspen stands is also key. This can be done by pruning crowded plantings to allow more air flow and by avoiding irrigation water landing on the leaves of aspen trees. Preventive fungicide applications are another treatment option. The first application is made at bud break followed by a second treatment 10 – 20 days later. Ideally, these applications would continue until environmental conditions that favor the disease formation have passed. However, the number of treatments required for ideal control is not a practical solution for most homeowners. Thus, Earth-Wise typically does two preventive sprays – not in an attempt to completely eradicate Marssonina from your property, but rather to keep the disease at non-damaging levels. Given the spring weather that we experienced in 2009 and 2010 and the high levels of Marssonina blight that we saw in the area, it is safe to assume that there are a greater number of fungal spores waiting to infect trees this spring. Please contact us if you have questions regarding this disease and how it may impact your aspen trees.

Aeration - It's Not Just for Lawns

Proper soil aeration is critical to the health of your trees because roots need oxygen to grow and function properly. An ideal soil is made up of 50 percent solids (silt, clay, sand and organic matter) and 50 percent pore space (air-filled and water-filled pores). However, very few landscape soils fit this profile. Typical development and land use compacts the soil and eliminates pore space, creating an unhealthy environment for your trees’ roots. Fortunately, there is a remedy. Properly amending the soil with organic matter, fertilizing and mulching will all help reduce soil compaction. A recent study showed that the above applications along with air tillage of the soil reduced compaction for at least three years after the treatment (Wells et al. 2009). You can’t have healthy trees without healthy roots. And healthy roots require aeration.

Green Solutions from Earth-Wise

Earth-Wise remains committed to providing quality plant health care services while leaving a small environmental footprint. To this end, we have always utilized cutting edge application methods and products: Applications made via soil/trunk injections and low-volume backpack sprays are examples of tools used to minimize the risk of exposure to non-target areas. Products such as horticultural soaps and oils, neem oil and pyrethrins allow us to effectively control many common landscape pests such as aphids, mites and scale insects. The use of pheromones offers some control of bark beetles like mountain pine beetles, spruce beetles and Douglas fir beetles. We can also maintain healthy, vigorous trees with an organic fertilization program. If you would like more information about moving your treatments in an organic direction, please contact us to discuss the specific options for your landscape. Excerpts from 2010 Earth-Wise Newsletter

An Ounce of Prevention...

Many of the pest problems we encounter on landscaped trees are secondary in nature. In other words, they are due to unrelated stress. This stress can be traced to many sources, such as poor nursery stock, improper planting techniques, and lack of maintenance. All of these cultural factors affect the health of your landscaped plantings. Selecting the right plant for the site is the first step in the process of creating a beautiful and healthy landscape. Is the site predominately dry and windy? Is the site predominately shady and moist? What are the conditions at the site and will the chosen trees or shrubs do well there? Local nurseries or landscape professionals can help with species and cultivar choices that will best suit your specific needs. Many times the nativity of the tree in question will tell you a great deal about conditions it will tolerate and thrive in. Even native selections can be challenging because they may have been grown far away, in a different climate, at a wholesale nursery or tree farm. This can affect how well these plant materials will acclimate and overwinter in their new environment. Time and care should be taken when choosing from available stock. Watch for injuries to the trunk, loose root balls and signs of insect/disease infestations. Avoid disturbing the root ball during transit or dropping it from the back of a truck. Even a small drop can damage the root hairs inside the root ball and result in additional stress to the plant. Correct planting and installation of your trees and shrubs can greatly increase your investment’s long-term health and quicken root establishment to allow for stronger, healthier growth. Here are some guidelines:

• Dig a hole that is about the same depth as the container or root ball. Dig the hole two to five times wider than the container or root ball; this allows for quicker lateral root growth. The wider the tilled or turned area, the better the roots will establish.

• Determine the height to plant. Do not plant too deep; roots need to breathe. If transplanting out of containers, the top level of the root ball in the container should be slightly above grade to allow for some settling. Score or break up the roots slightly to encourage fibrous root growth. Cutting any circling roots at the time of planting will reduce the possibility of girdling roots in the future. Supplements are encouraged, but high nitrogen fertilizers should not be used the first season.

• Be careful handling your plants. Always move by the root ball and avoid damage to the trunk and crown. When transplanting balled and burlapped trees and shrubs, look for the root collar at the top of the root ball – this is the level for proper planting. The root collar should be slightly above grade to allow for some settling. Remove at least two thirds of the burlap from the top down (if the wrap is plastic or synthetic, remove completely). Cutting off the basket with a pair of bolt cutters is recommended after the tree has been placed at the right height. Moving the root ball after unwrapping the burlap and removing the wire basket and twine is not advised. Cutting off the top two thirds and leaving a small amount of wire basket on the very bottom is usually the best way to remove the wire that could later girdle your roots. This allows one to place the tree in the hole and adjust its position with the support of the wire and twine, and then remove once the positioning is complete.

• Backfill with loosened soil and firm the soil around the root ball. Do not pack soil too tightly, as again, the roots need to breathe. Create a berm of soil on the outside edge of the planting hole 3 to 6 inches high – more for larger diameter trees – to direct water to the root zone when irrigating.

• Water in thoroughly the first time and check in two to three days. On a weekly basis, use five gallons of water per inch of diameter. For example, use 50 gallons per week for a 10 inch diameter tree. Deep, infrequent watering is better than small amounts of water more often. This creates better root structure and encourages deep root growth.
 

• Staking is important, especially where high wind exposure is expected. Leave some room where staking is attached to the trunk – this will keep the bark from being damaged during wind and allow for a small amount of lateral movement which actually strengthens stems and trunks. Remember to remove these stakes and straps after one year. Bare wire should be padded or tree strapping should be used.

• Mulching completes the process. Two to three inches of mulch conserves moisture, cools the roots, and reduces weed pressure. Mulching around trees and shrubs also reduces mechanical damage from mowers and trimmers to trunks and low limbs/branches. This damage is a perfect entry point for disease and insects!

Proper fertilization and pruning comes later in the tree’s establishment. Application of a high nitrogen fertilizer is not needed at the time of planting; we want to encourage as much root growth as possible in the first season of establishment. (Although applying a rooting /nutrient supplement is fine because the nitrogen is usually limited and the nutrients needed for good root growth are there in readily absorbable forms.) Removal of diseased branches and limbs in the early spring or fall will reduce the spread of fungal pathogens. Continue with structural and sanitary pruning every season as needed and begin a regular fertilizer program to ensure vigor and quality of growth. Improved cultural practices will reduce stress in your plants that often leads to pest outbreaks, reduce the need for pesticide use, and increase the efficacy of treatments when they are necessary.

Location, Location, Location

We often hear realtors use the expression “location, location, location” when talking about factors that drive real estate prices. We should hear landscape design companies say the same thing when it comes to the success of newly installed landscapes. The location of their planting site is critical to the long-term health of trees and shrubs. Examples of common challenges that plants face due to poorly designed landscapes are:
 

• A tree that someday will be 50 feet tall installed just a few feet away from a house or in a location that offers limited opportunity for root growth.

• A desert plant installed in turf grass in a low spot.

• A water-loving plant installed on a berm that drains irrigation away from its roots.

If these plants survive, they will be stressed and require more maintenance than a properly placed plant. That is why, when considering installing new plant material, the first step should always be to hire a professional landscape company – a company with the expertise to design a landscape that will not only survive, but thrive. A company that knows it’s all about “location, location, location”.

Tree Tips for Holiday Lighting

Many of us enjoy lights in our trees during the holiday season. But did you know that leaving holiday lights on your trees year round can cause girdling damage to the trunks. As the tree grows each season, it adds diameter to the trunk. If electrical wires and/or lighting are left wrapped tightly around it, they can begin to constrict the trunk. Over the course of a few seasons this can reduce the flow of nutrients and water in the tree. Every year we see stressed, and sometimes dying, trees due to holiday lights left in place. So remember, when you’re done enjoying your holiday lights, put them back into storage. Your trees will thank you for it! Excerpts from 2009 Earth-Wise Newsletter…

Mountain Pine Beetle Still Poses Threat

Due to the devastating effects of mountain pine beetle throughout Colorado, we feel compelled to remind you which tree species are vulnerable to attack and what the best strategies are to protect your pines. As most of you know, mountain pine beetle has already arrived in the Roaring Fork Valley. This insect is native to Colorado and attacks several species of pines. Ponderosa, lodgepole, Scots and limber pines are the most common hosts. The best management practices for mountain pine beetle control are to reduce beetle populations by removing infested trees and spraying high value trees to protect them from attack. The spray should be done in the early summer prior to beetle flight, which typically occurs in July. Likewise, infested trees should be removed prior to beetle flight. Once trees are removed it is important to properly dispose of the wood in order to kill the insects before they emerge. This can be achieved by: peeling the bark off, placing the logs in a sunny location and covering them with a clear plastic tarp to raise the temperature sufficiently to dry out the cambium, or disposing of the logs in a landfill where they will be buried. Earth-Wise has made, and continues to make, a concerted effort to identify vulnerable pine species and offer a preventative spray on all of the properties that we manage. If you have a question or concern about pines on your property, please contact us so we can ensure the necessary steps to protect your landscape are being taken.

Willow Scale Study Update

As some of you may recall, Earth-Wise worked in conjunction with the Colorado State Cooperative Extension last year to determine the optimum rate to apply Safari insecticide (through soil injections) to achieve effective control of willow scale, an insect that infests aspens, cottonwoods and willows. Earth-Wise chose several sites in Aspen to conduct this trial and CSU performed the applications. Contrary to our expectations, the preliminary data shows a significant decline in control as the application rate was decreased from the maximum label rate. However, we don’t consider these findings conclusive yet and will be working with CSU again this year to duplicate the trial.