Tree & Shrub Care

There is considerable discussion about the proper time to apply fertilizers to trees. The practice of applying N-P-K fertilizer to trees in the fall is common in the arborist and landscape industries, even in the northern zones. Is this practice a good one, or not?

Extensive research has proven that the presence of abundant mycorrhizae and beneficial rhizosphere bacteria greatly improves the survival, growth rate, and disease resistance of plants compared to plants lacking these.

Extensive research has proven that the presence of abundant mycorrhizae and beneficial rhizosphere bacteria greatly improves the survival, growth rate, and disease resistance of plants compared to plants lacking these. This is particularly true for plants growing in stressed or degraded sites, urban environments, drought conditions, and compacted soils. .

The following article lists the Mycorrhizal Types on Important Plants.

PHC for trees is uniquely different from other fertilizer formulations currently on the market. Unlike the competition, PHC for Trees is not a mere random mixture of fertilizers. Instead, it was formulated to address several problems associated with fertilization: quality, uniform delivery, even distribution of nutrients in the soil, and sustainability.

Commercial tree care companies provide a range of services that include spring or fall fertilization typically applied by soil injection, or occasionally by vertical mulching, radial trenching, or even by drench. The timing of these treatments typically vary depending on local practice or practical limitations.

Root feeding systems inject solutions of various kinds into the root zone of established trees and shrubs. Examples of injected treatments include, fertilizer, mycorrhizal fungi, and rhizosphere bacteria, among other things. With all these treatments, water is used as the carrier to deliver the active ingredients into the root zone.

A drought is a particular stress that can have short and long-term effects on tree health. These effects should be taken into consideration when planning a fall fertilization treatment subsequent to a severe drought.

This is a common issue encountered by landscapers who apply arbor fertilizers by soil injection. Fertilizers that have at least 50% slow-release nitrogen are recommended by various experts, including the American National Standards Institute (ANSI). However, these slow-release fertilizers typically have poor water-solubility, so that undissolved particles may settle in the tank, or worse yet, can clog screens or mechanical parts. Why can’t anybody make a slow-release fertilizer that fully dissolves in water?

Select a tree that is suited to your location and climate. That will help insure success. A tree that is balled and burlapped should have a sufficiently large root ball: about 1 foot root ball diameter for every inch of trunk diameter. For example, a shade tree with a trunk diameter of 2 inches should have a ball that is about 24 inches in diameter.

Radial trenching involves drilling or digging narrow trenches beneath the canopy arranged like spokes of a wheel around the trunk. Typically, you would start a trench near or beyond the dripline and trench toward the trunk, stopping no closer than 6 inches for each inch of trunk diameter.

Soil Injection is a fairly common procedure used on trees to achieve any or all of the following goals:

  1. Fertilization of the soil
  2. Inoculation of the Root Zone

Vertical mulching, also known as “vertimulching” is a fairly common procedure used on trees to achieve any or all of the following goals:

  1. Aeration of the soil
  2. Partial decompaction of the soil
  3. Fertilization of the soil
  4. Inoculation of the Root Zone