By: Anthony C. Arnoldi, Board-Certified Master Arborist WI-0102B
- They have suffered from thinning root systems during the last five years of the accumulating drought
- Boring insects have risen to extremely high levels and are attacking various species.
- Chlorosis has begun or intensified on susceptible trees
- Needle diseases and needle drop of evergreens are commonly visible.
- Fungal leaf diseases of deciduous trees are causing defoliation.
- Root rots have affected many root systems.
- Dieback and decline has started on many trees
All of these are working in varying combinations to leave our trees stressed and vulnerable to further insect and disease attack. Some are not ready to endure another long winter.
Fertilization is one of the most powerful tools arborists have at their disposal to help trees recover from stress and damage. It is often necessary to help trees by controlling insect or disease attack but as far as providing aid that actually improves tree health; fertilization is the cornerstone.
Several options in fertilizer formulation enhance our ability to help your trees recover and avoid potential problems:
- Polymer-based nitrogen in a specially balanced complete fertilizer. This allows us unmatched control with slow release for an entire year without “pushing” the tree or stimulating unwanted growth. It provides the necessary elements for growth, defense, replacement leaves or roots and compensating for environmental stresses.
- Root biostimulant and humates option for tree fertilization. This more “green” approach enables the roots to be targeted. This is often necessary to compensate for drought, construction damage or root rot. It is invaluable in assisting trees without stimulating root rot, shoot blight or other diseases. It is indispensable in encouraging newly planted trees to become established, especially in our difficult, clay-based soils.
- Mixing root biostimulant combinations with varying levels of complete fertilizer. This provides for special applications and requirements based on the tree condition and insects and/or diseases present.
- Chelated iron, or manganese alone, or as an inclusion to fertilization, can help to fight or prevent chlorosis or micronutrient deficiency.
Your Certified Arborist is best qualified to choose the right options and combinations to design the program tailored for your specific situation. Fall is the perfect time to fertilize because roots naturally peak their growth as the leaves shut down for the year. Fall fertilization can enhance this peak and promote greater pick up of the soil-injected materials. This will better prepare your tree for a long winter and help it to be able to successfully “wake up” next spring!
© Copyright 2009 – Wachtel Tree Science & Service, Inc.