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!