Rooted In Care – A Guide To Tree Health
by Cheryl Lafferty, CCMGA Master Gardener Intern
I live in a planned community with around 2,000 single-family homes, and similar neighborhoods are springing up nearby. What was once a small farming town, Princeton has rapidly transformed into one of the fastest-growing cities in the United States. In my community, each new house comes with a tree planted in the front yard. There are a variety of trees being planted, and the potential impact of those trees reaching maturity is exciting—both for their beauty and for the physical and mental health benefits they provide. However, three years into moving here, I’ve noticed a few common missteps when it comes to caring for trees. I hope to explore what contributes to healthy, thriving trees over the next several issues of Garden Wise Gazette and share what I’m learning. Maybe together, we can save a few trees by better understanding how they grow and how to care for them.
As we prepare our beds and lawns for winter, we need to consider how we will care for our trees as well. Trees serve us during the summer by providing shade from the hot Texas sun. In the fall, they shed their leaves to allow the warming sunlight through their bare branches in time for the cold winter. They provide shelter for wildlife, clean the air and enhance the curb appeal of our homes. Caring for them is a small investment that yields lasting rewards.
Appropriate mulching and watering continue to be necessary even if the tree looks like it’s not active. The mulch we apply doesn’t need to, nor should it, be removed as we add more. Mulch becomes compost, which feeds the soil and allows air to move through the clay. A two-to-three-inch thickness of mulch is ideal, spread evenly and kept from building up around the trunk. Just underneath the tree bark is the vascular system that sends nutrients and water up and down the tree. The bark, too, should be cared for so it can protect the tree and facilitate healthy growth.
As the leaves collect on the ground, it’s tempting to want to rake them into bags and put them on the curb. And depending on how many leaves you’re left with, you might have to dispose of some of them. But those fallen leaves can return nutrients to the soil. Particularly in a new development where the soil has been scraped away, returning nutrients is critical. Running a mower over the leaves can break them down enough to start the composting process over the winter. The compost created by mulching leaves and allowing them to remain on the ground feeds the organisms that live in the soil and will produce carbon, which trees use a lot of. Trees are very much alive during the winter months and continue to require all the good things that come from the soil.
Watering your trees throughout the winter when temperatures are at least 40 degrees will keep your tree healthy and give it a good start for new growth in the spring and summer. A lack of water is a major stressor for trees throughout the year. Established trees will need about 15 gallons of water once every month. They like a slow, deep drink.
Pruning trees is also best done in the winter months in order to reduce pathogens that could enter the tree at the cut and to reduce the amount of sap the tree loses. Pruning is done for a variety of reasons. Removing dead branches will prevent them from falling later and creating a safety hazard. Structural reasons include increasing the canopy to allow for more airflow and sun exposure to leaves and fruit, and in some cases, removing lower branches can improve the overall shape of the tree. Just keep pruning to no more than 20% to 25%. I’m personally comfortable pruning any branches I can reach from the ground. For higher branches, or if you have questions about the structural impact pruning will have on the tree, you should consider calling an arborist to keep both you and your tree safe.
If you have a new tree and it is staked and tied, it’s likely time to remove the ties from the trunk. It’s recommended that we leave the tree tied to the stake for as short a time as possible, which is typically no more than a season. If a tree is healthy and has been properly cared for, the roots should be in place to provide support to the tree after that amount of time. If it is tied too long, you will find an indentation under the tie. This is called “girdling” and indicates damage. This kind of damage will prevent the circulation of water and nutrients that take place right beneath the bark and will impact the growth of new bark. Tree factoid: Girdling is actually a strategy sometimes used to intentionally kill trees. Your tree’s roots should provide sufficient support to keep it upright, even during wind. In addition to storing carbohydrates and sending water and minerals up through the tree, roots provide essential stability. They instinctively grow in the right direction to keep the tree thriving.
We’ve covered a lot of ground for the first article in our tree care series, but there’s so much more to explore. This is just the beginning of our journey into tree care in North Texas. Stay tuned as we continue exploring ways to help your trees grow strong and healthy!
If you’re eager to learn more, here are some great resources to help you get a head start on your tree knowledge.
https://extension.unl.edu/statewide/dodge/the-benefits-of-fallen-leaves/
https://www.fs.usda.gov/learn/trees/anatomy-of-tree
https://extension.umn.edu/planting-and-growing-guides/staking-and-guying-trees
https://extension.umn.edu/yard-and-garden-news/winter-good-time-prune-trees-and-shrubs
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