We love our trees. Trees have a cooling effect in our yards by providing shade and they increase property value. When our trees do not “look good,” we try to help them, but when that one “magic” application does not solve the issue, we are often discouraged. A proper plant diagnosis will help your trees and save you time, money, and energy when dealing with the problem.
Damage to your tree can be caused by a living organism and/or environmental factors. Fungi, bacteria, viruses, nematodes, mites, insects, and animals fall under the living organism category and these tend to attack specific plants. Environmental factors that could affect trees include drought stress, salt injury, chemical injury, winter damage, improper planting, watering, and growing conditions, among others. Damage caused by living organisms can be similar to the damage caused by environmental factors. Here are a few tips to help you conclude what is causing damage to your tree:
First, identify the tree and how old it is. Knowing this will help you become familiar with the best growing conditions for that tree, and what kinds of insects and diseases are specific to it.
Inspect the tree – take a thorough look at the trunk, branches, and leaves. What abnormalities do you notice? Are the leaves discolored, bite marks, abnormal growth, unusual size, odd branches, or is the trunk oozing? What color is it? Does it smell? Do you notice any injuries or scars? Any holes? What size and shape?
Look at the environment where the tree is growing. How was the tree planted (burlap, chicken wire, planted too deep, girdling roots)? What kind of soil is it planted in (sandy, clay, poor drainage, compaction, etc.)? Is the tree near a foundation, driveway, traffic areas, wall structures, etc.? Any construction or change in the landscape around the tree area?
What watering conditions has the tree been subject to (water at the dripline, how much water, water throughout the year, etc.)? How is the water system checked? What is the soil coverage around the tree (rock, bare soil, lawn, organic mulch, etc.)? Any chemical application (herbicide, fertilizer, insecticide, etc.)?
Gather other information. Pictures help a lot to see how the issues have progressed. Collect any insect samples. Record when the symptoms started to appear.
All this information is crucial because symptoms caused by environmental factors can be like those caused by living organisms. In some cases, a lab analysis might be the best option to confirm or dismiss the presence of a pathogen and will help you develop a treatment plan.
Consider this common scenario: A 15-year-old tree grows next to a paved driveway and a wall, with gravel mulch around the base. Underneath the gravel is a plastic layer of weed fabric.
Shallow roots due to heat stress and limited watering. Photography Courtesy of James Vocasek c/o KRQE.com
The tree does not receive enough water for many years and gets no rainwater through the weed fabric. This tree is struggling to develop a good root structure and starts looking unhealthy. Eventually the tree gives up and a strong wind brings it down. In this case, chemical treatment will not improve the tree’s appearance because it is not addressing the true cause of the problem: watering improperly.
Diagnosing what is wrong with your tree will take time, but it is worth it. These local resources can help:
Author: Sara Moran, Extension Horticulture Agent, Bernalillo County, NMSU Cooperative Extension Service. Have a question about the article? AskAnExpert@abcwua.org
The balancing act of watering your trees in the fall and winter is important. Established trees should be watered two to three times a month in the fall season and once a month in the winter season. If not watered properly, trees that get too dry during this time can suffer stress and drought injury. This often does not show up until the heat of the following summer, which then makes trees more susceptible to pests and disease. Fall is the time to set your trees up for winter success.
Other important factors to consider when watering trees:
Newly planted trees (trees planted within 1-3 years), are more susceptible to damage from dry conditions and should be watered more frequently than established trees. Try watering them to a depth of 24 inches three times a month in the fall and twice a month in the winter.
Evergreen trees lose water through their needles in the dry winter air. They need more stored-up water going into the winter season to make up for that. Cold, dry winds can strip water from evergreens faster than their roots can absorb it, too. That is why it is especially important to provide enough water in the fall and during dry, warm spells in the winter.
Even though they lose their leaves, deciduous trees should also not get too dry in the fall and winter. Water acts as an insulator for both the tree and soil. Soil that stays moist will be warmer. Likewise, plant cells that are plump with water will be less susceptible to damage from the cold. Water deciduous trees to a depth of 24 inches twice a month during the fall and once a month in the winter.
When watering any tree, remember to apply water out to the edge of the tree’s canopy drip line. Most established trees have a root spread equal to their height and beyond. Water deeply and avoid spraying foliage. Watering to the right depth depends on your specific soils, so you will want to measure how much water it takes your soils to reach 24 inches deep. Read this article for tips on measuring watering depth.
One of the best things you can do for your trees in the coming months is to add mulch. Layering three to four inches of organic mulch protects the soil from moisture loss and helps regulate soil temperature throughout the winter. Treebates for bulk organic mulch is available.
Pro Tip: "Watering to the right depth and managing the frequency of watering are both very important aspects of keeping our plants healthy throughout the year, but especially in the fall and winter months,” says Patrick Chavez, Trees of Corrales Wholesale Nursery.
Author: Amos Arber, Xeriscape Incentive Inspector, and Certified Arborist with the Water Resources Division for the Water Authority. Photography: Wes Brittenham Pro tip:Trees of Corrales Have a question about the article? AskAnExpert@abcwua.org
Water Authority customers have been inspired to convert their turf to sustainable, resilient xeriscapes that save water, time and money and provide habitat for wildlife and pollinators for many reasons. Below are some of our favorites:
“We just didn’t see the point of maintaining and paying to water the grass in the front yard. No matter how much we water and fertilize, the front lawn never looks good, and we don’t want to be the last house on the block with a not-so-great lawn.”
“Now that the kids are out of the house and we no longer have dogs, we don’t want to have such a high water-use landscape that requires weekly maintenance. We want to do our part in saving water for future generations and create a beautiful patch of nature in our backyard, especially now that we’re into birdwatching.”
“We may downsize someday, and our realtor said that having a beautiful low water use landscape is a good selling point.”
“We just moved to Albuquerque from another part of the country where grass grows easily, and we spent several hours a week mowing and weeding. We are done with mowing. We want a landscape that is regionally appropriate, with native and low water use plants and trees.”
“Our irrigation system seems to always need repair, and the grass never really looks that great.”
“We needed to replace our sewer line which meant digging up the front yard. It seemed like a good time to ditch the grass and convert it to a low maintenance landscape with new drip irrigation.”
Qualifying conversion projects by Water Authority residential customers may receive $1.00 per square foot of converted turf grass. This rebate has a specific application process. Only projects that have completed the application and passed inspections will qualify for the rebate. For more information visit our rebates page.
Pro Tip: Are you ready to convert your lawn to a xeriscape? Here is what local landscape contractor Tyson Hafler, owner of Southwest Horticulture, wants you to know before you start.
“Make sure you start with a green lawn. It is important to have a green lawn for two reasons. Water Authority needs to see a currently cared for, in good living condition green lawn to quality for the rebate. A live, green lawn is much easier and speedier to get rid of than a brown, dry, dead and dying lawn.”
Author: Amos Arber, Xeriscape Incentive Inspector with the Water Resources Division of the Water Authority. Pro Tip: Tyson Hafler, Landscape Contractor and Owner, Southwest Horticulture. Have a question about this article AskAnExpert@abcwua.org
Your irrigation system is only as good as its aim. Adjust sprinklers and emitters to make sure they are delivering water to the landscape and not onto rocks, bare earth or pavement.
June is a great time to check and replace any clogged spray nozzles or drip emitters. Remember, each spray head also has its own filter insert that needs checked as well.
Watering Recommendations: Summer is here and so are hotter temperatures! Follow the Water by the Seasons Summer watering recommendations to keep your yard looking healthy. For turf, water 2-3 times per week. Start watering your trees and shrubs 1 time per week to keep them looking good.
Remember, if it rains more than a half inch you can skip your next scheduled watering as there is no need for supplemental irrigation.
Our urban forest (yes, the trees in your landscape are part of a forest) provides so many benefits too us – cooling, increased home values, beauty, and better mental health just to name a few.
Here’s what you can do to help keep your members of our urban forest as healthy as possible.
1. Water your trees to a depth of about two feet, because 95% of the tree’s roots are in the first two feet of soil. To check if you are getting down to that two-foot optimum, insert a long screwdriver or soil probe into the soil around your tree a day after watering to determine the depth the water has reached. Adjust your watering time, if needed, to reach that two-foot goal.
2. Water your trees a little inside and outside of the canopy edge (the outer ring of the tree’s leaves) because that is where the roots that take in water are located.
4. Check your trees for signs that they aren’t getting enough water: wilted leaves early in the morning, scorched leaf edges, twig die-back from the top down or a sparse leaf canopy.
5. Take advantage of rainwater by directing downspouts or canales toward existing trees. Consider planting new trees in lower areas to take advantage of captured moisture.
6. Surround your trees with 4-6 inches of organic mulch. Organic mulch helps to retain soil moisture, keeps soil temperatures more consistent, and keeps weeds out. Additionally, over time it loosens compacted soil, adds organic matter, and slowly adds nutrients to the soil. Note: organic mulch does not include bark (sometimes called ‘bark nuggets’ or ‘deco bark”). Use actual wood chips like what comes out of an arborist’s woodchipper. Many tree services offer wood chips for free and several local businesses sell wood chip mulches in bulk.
Author: Amos Arber, ASLA, ISA Xeriscape Incentive Inspector with the Water Resources Division for the Water Authority. Have a question about the article AskAnExpert@abcwua.org
The amount of water needed and where that water should be applied changes as woody plants (such as trees, shrubs and vines) get larger. Woody plant material has two types of roots, stabilizing roots and feeder roots. Both types of roots do just what their name implies. Stabilizing roots are thick and dense to keep the plant in place and support its weight. Feeder roots are super fine and grow more like a net to take in water and nutrients. Feeder roots expand out as the plant grows.
Some woody plants require more water as they mature, but more desert-friendly species may not require extra water or may even be able to survive without supplemental irrigation once established. Perennials normally do not need to have expanded watering the same way woody plants do as they mature.
Some examples of this:
Plant Type
Plant
1st summer
2nd summer
3rd summer
Tree
Desert Willow (Chilopsis linearis)
60 gallon per month
120 gallons per month
400 gallons per month
Shrub
Butterfly Bush (Buddleia davidii)
60 gallon per month
70 gallon per month
100 gallon per month
Desert-Friendly Shrub
Chamisa (Ericameria nauseosa)
20-30 gallons per month
20-30 gallons per month
Usually possible to remove from irrigation
Vine
Trumpet Vine (Campsis radicans)
40 gallons per month
60 gallons per month
100 gallons per month
Woody Groundcover
Prostrate Sumac (Rhus trilobata)
20-30 gallons per month
40 gallons per month
60 gallons per month
For those plants that do have increased irrigation needs as they mature here are three easy ways to apply the right amount of water in the right place depending on the type of irrigation you are using.
Drip Emitters – Move the drip emitters out to stay in line with the outer edge of the plants leaves where the feeder roots will be. Increase the number of emitters watering the plant too, placing them evenly around the outer perimeter of the plant.
Netafim (in-line professional drip line) – this is typically installed in rings around the plant and additional rings can be added as the plant grows larger. Netafim can also be laid out in a grid pattern, particularly when being installed around an already established plant.
Hand-watering – Build and maintain a watering well at the outer edge of the plant perimeter. As the plant grows, increase the size of the well.
Author: Richard Perce, Irrigation Efficiency Specialist with the Water Resources Division for the Water Authority. Have a question about the article AskAnExpert@abcwua.org
