Leaves are often the first thing you notice about trees. Healthy leaves should be vibrant and full, with a broad spread. The color should be rich and right for the season. Tree leaves should fill the crown and give a tree’s shape a lushness that draws you in.
Beyond adding beauty to your yard or landscape, tree leaves are storytellers. A tree with healthy leaves will not only catch your eye with its beauty, but it will also tell you a lot about the overall health of the tree and its environment. Trained arborists, like those at Mr. Tree, can help you read the tree leaves and make a plan with you to preserve the health of your trees for years to come. In this article, we’ll go over five things you can learn from tree leaves.
1. Tree Leaves Are an Indicator of Overall health
Healthy tree leaves can also tell us a tremendous amount about the tree roots and soil. Healthy conducting tissues start in the roots and allow water and nutrients to flow up through the tree from trunk to branches efficiently and effectively. When the flow is right, the leaves will get what they need to be healthy and last through the growing season until it’s time for them to show off brilliant fall colors.
Just as you might notice at first glance that a house has siding missing or broken windows and needs a little work, a tree with gaps in the crown, discolored leaves, or leaves on only part of the crown may need a little help too. It can also tell you that something bigger is happening that you need to pay attention to.
2. Root and Soil Health
Healthy trees need a healthy root system and soil to really thrive. If only we could look under the tree from time to time to help us know how the roots are doing, but since that’s not possible, we can instead look for clues in the leaves.
While vibrant leaf color tells us a root system is healthy, leaf discoloration can be an indicator that the root system isn’t drawing much-needed nutrients and water out of the soil. There are a lot of possible reasons, including compact soil, a mismatched pH level, trenches or close construction, moisture levels that are too high or low, and even competition from the roots of other plants and trees.
While you might be able to change some challenges to roots and soil, a trained arborist can help you understand what the roots and soil need and make a plan with you to combat the issues and help your tree regain its health.
3. Nutrient Deficiency
Nutrient deficiency starts with the roots and soil, but the leaves have a lot to say about it too. A common indicator is discoloration, which can tell us what kind of nutrients are missing or perhaps are too abundant. The pH level can also affect how a tree absorbs the available nutrients. A mismatch can prevent a tree from drawing up what is around it and affect its overall health. It would be like sitting in a restaurant and seeing everyone else getting served but you.
Leaves that are yellowing at the outer edges but have retained green at the leaf veins may have interveinal chlorosis, which can start with a deficiency in manganese or iron. Leaves that are yellowing fully may have chlorosis, which might indicate a nitrogen deficiency. Over-fertilization can cause some issues as well and leave too much phosphorous in the soil, causing additional tree leaf issues.
Tree leaves tell us a lot of things about these issues, but a soil test is a good starting point to understand soil health and the balance of nutrients in it. Soil test results will help you interpret what you’re seeing in the tree leaves and help you understand what the soil needs to help your tree regain its health.
4. Water Stress
Just as too much or too little water can cause imbalances and issues for people, a tree can also be stressed by soil water levels. Tree leaves are the first place you can see water stress. Leaves may wilt or even die and fall off prematurely if water levels are imbalanced.
Brown blotches that work their way from the outer edges throughout the leaf can be a sign of drought stress. The outer edges aren’t getting the water they need, and slowly, the rest of the leaf is affected. This can be a concern at any time, but it’s especially challenging in a dry, hot summer.
Taking action when you first spot the issue can save the tree. Start increasing your watering routine and water regularly to ensure they get a good soaking, then monitor your tree to see if additional care is needed. Mr. Tree has trained and certified arborists who can help you understand how to care for your trees through even the toughest drought season.
5. Insect Damage and Disease
Tree leaves have so much to tell us, but they offer something else—food for insects. Trees have a critical place in a healthy ecosystem, and insects are part of that. However, insects can also cause significant damage to trees and jeopardize their health.
Leaves are especially vulnerable and show damage immediately. Some insects, such as gypsy moths, aphids, weevils, and leaf rollers, lay eggs on hardwood tree leaves or evergreen needles, then the larvae decimate foliage. Catching these pesky bugs early can help ensure you minimize damage to your tree.
When a tree is left vulnerable, it can also become the victim of diseases that manifest in leaf damage but indicate deeper issues. Blights, mildew, and other diseases can severely damage the overall tree, leading to stunted growth or even death.
Regardless of the issues your trees face, Mr. Tree is here to help you care for your trees so they can be a beautiful part of your landscape or yard for years to come.
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