Written by: Jean Ferdinandsen, Certified Arborist WI-0149A
I think of an I.V. (intravenous) treatment as a way to get necessary nutrients and medication into a person for faster results. This can also be done with trees for certain issues and at certain times of the year. One of these issues is a nutrient deficiency which causes chlorosis. White oaks as well as birch, maples and other species can often be prone to chlorosis in our area, typically showing symptoms in summer. The causes may be various.
- Periods of drought alternating with waterlogged soils cause root fine root loss, reducing nutrient and water uptake.
- Root rot fungi can attack roots with similar results
- A mismatch of tree type and soil may lead to poor long term results
Soils in our area are typically heavy and a have high pH. This high pH keeps iron and other micronutrients tightly bound to the soils and unavailable to the tree. The result of compromised or stressed root systems and high pH, is that trees are not able to absorb necessary nutrients. When this happens, trees may lose their green color and are unable to synthesize enough chlorophyll. Chlorophyll is the green substance that manufactures food for the tree. Without it, the tree is starving.
The symptoms of chlorosis (starvation) may include:
- Yellow leaves with green veins
- Smaller than normal leaves
- Scorched leaf margins
- Crown thinning
- Tree decline and eventually death
Chlorosis may appear slowly as tree health declines. Regaining tree health may also be a slow process. However, macro-infusion trunk injections of micronutrients, primarily iron, can give marvelous results more quickly. Called FAC, this very mobile iron is capable of greening up trees quickly and for up to 3 years.
Small holes are drilled into the base of the tree and the FAC solution is injected into the tree under low pressure. It provides a strong green up in a short time and is especially useful in cases with advanced chlorosis or that have not responded to other treatments. Injections are done in the fall to avoid causing leaf drop. Next spring, leaves are often dramatically greener and “starvation” is averted. Green up may not be uniform throughout the tree based on how the FAC is taken up.
Additional treatments or cultural recommendations may be made to continue your tree on its road to recovery. Wachtel’s Certified Arborists can access your tree now to see if a FAC trunk injection may be the most effective and economical way to turn your chlorotic tree around. Contact us today for an evaluation.