Whether through roots, or applied to the surface, one warning sign I know of is if a company offers the fertilizing as a ROUTINE service, without much thought about soiil tests or diagnosis.
Some companies out our way, just apply it on schedule like mowing a lawn, just not weekly.
We get a lot of wind, rain and occassional ice here, and a lot of fertilized trees - even for better causes - receive heavy damage due to extra growth.
The branches are longer, thus more leverage in the favor of ice, snow and rain weight. And the leaves are bigger, or needles, providing more surface area for precipitation to build-up weight.
So in one way, some of the slightly nutrient deficient trees, hold up better than the properly fed ones.
Its a fine service when a trained specialist uses it sparingly. |