Trees Chlorotic? Green Trees Up with Micronutrient Injections
August 10, 2019
When it gets HOT here in Texas, we often see trees go yellow. Why? When the soil heats up, and soil pH is high (as it is here in N. Texas), plants can have a tough time taking up certain important nutrients. These deficiencies can often result in chlorosis. What is chlorosis? It’s a fancy term for the yellowing of the leaves due to the lack of chlorophyll. In extreme cases, the yellowing can cause leaf drop, weakening growth, and twig and branch die-back.
Chlorosis can be caused by many factors, but most commonly in Texas is caused by the lack of certain nutrients (often Nitrogen or Iron) due to our high pH. Other causes of yellowing of leaves in our climate include drought, high temperatures, soil compaction due to heavy rainfall, poor drainage, leaching of nutrients, and restricted root growth from all of the above.
The pH scale runs from 1-14, with optimal soils allowing for best nutrient uptake in the 6-6.5 range. Our soils in North Texas are high side of the pH scale – 7.0 or above, often in the 8.0+ range. In a high pH soil, certain nutrients become unavailable for plants to take up and use; essentially they are what we call tied-up. Nutrients that commonly become tied-up are Iron (Fe) and Manganese (Mn), which are important micronutrients that allow plants to form chlorophyll. When soil temperatures get hot in a soil with high soil pH, Nitrogen (N) can also be deficient.
Soils can vary greatly over a particular area due to compaction and soil removal from construction. We recommend soil tests to fully understand your soil composition.
Unfortunately, many landscape plants that are planted regularly in our area actually prefer acidic soils (below 6.5 on the pH scale). This includes plants like nandina, hollies, oak, pears, azalea, maple, magnolia, and hydrangea - and many more. Such plants will often get chlorotic in the hot summer months. Certain fertilizers and nutrient injections may be necessary to get plants healthy again.
What can we do?
The good news is that micronutrients injections applied using the ArborJet system can often reverse the effects of chlorosis in your trees – although the length of time to see results can vary depending on the severity of chlorosis. We inject - directly into the tree’s vascular system - our special blend of micronutrients made up of manganese, iron, zinc, boron, and copper that can help correct deficiencies and get trees healthy again.
In addition to ArborJet injections, we suggest soil aeration for heavily compacted soils along with ongoing soil feeding as a part of our SEASONS tree program. Micronutrient injections are meant to help severely affected plants in severe cases of chlorosis. But getting your soil and trees on a seasonal care plan can help prevent major issues long-term.
If you have noticed increasing yellowing in your landscape plants and trees, contact us and our Plant Health Care technicians. We’ll help get the green back in your landscape.