Trees in cities rely on the people who cohabitate with them in their environment to notice when they’re sick or when they aren’t getting the right kind of nourishment to keep them healthy.

We offer a variety of Plant Health Care services to meet your trees’ needs – everything from fertilizing, soil amendment and protection from pests and disease. Let us build a custom care plan to help your tree be the best it can be!


ArborGain™ brings soil treatments to the next level. This proprietary product was developed by the Cohen & Master team to specifically address challenges that plants face when growing in urban soils. ArborGain™ is not a conventional fertilizer product, rather ArborGain™ is a soil conditioner and biostimulant. Formulated from humates, kelp and beneficial microbes, ArborGain™ promotes healthier foliage, stronger root development and heightened drought resistance. Healthy soils which benefit plants are highly active with biology. ArborGain™ delivers, feeds and stimulates this biology.

Protect your plants from urban stress and treat your plants to increased vigour, health and beauty.

Ask us about Arborgain!


Biochar is carbonized biomass (such as wood-chips). This transformation is achieved through a process of restricted oxygen, controlled temperatures and high pressure.

Biochar is an incredible tool for fixing depleted and compacted urban soils!

Biochar greatly improves poor soil in 3 ways:

  • Increases nutrient availability
    Nutrients cling to the biochar and remain in the soil longer, maximizing fertilizer treatments.
  • Increases water holding capacity
    This is critical in urban soil where water availability is almost always limited. Will help sustain trees through periods of drought.
  • Allows for beneficial microbes (fungi & bacteria) to thrive
    This is critical for healthy soils that facilitate nutrient uptake in plants e.g. Mycorrhizae fungus

Utilizing our specialized Air Spade equipment, open vertical columns are blown down into the soil in a grid pattern across the rooting area of the plant. The Biochar is directly mixed into our custom compost resulting in a microbe and nutrient populated Biochar. This mixture is then poured into the vertical columns, allowing for the beneficial mixture to blend with the soil profile at depth while taking advantage of the soil de-compaction achieved with the air spade.

Ask us about Biochar!


Mycorrhizae (my-cor-rhi-za) is a unique type of fungi that does not produce its own food source, and therefore relies on the roots of plants for energy. In exchange, the Mycorrhizae make water and nutrients available to the plant that they would otherwise be unable to access on their own.

Having mycorrhizae available in the soil is extremely beneficial to mature trees in an urban environment where soil disturbance has destroyed the delicate structure these organisms need to survive.

At Cohen and Master, we’ve created a custom product for Toronto soils that combines all the ingredients required to give the tree an immediate boost. However, we also recognize that living organisms are required to rebuild a soil environment where the tree can create and maintain a healthy root system on its own. By adding Mycorrhizae and bacteria, along with food sources and nutrients into the soil around your tree, you are providing these valuable landscape features with the resources needed to not only thrive tomorrow but to sustain themselves for decades.

Ask us about MYCORRHIZAE!


Soil renovation is the process of de-compacting soils to increases soil pore space, improve oxygen and carbon dioxide exchange, boost water infiltration and encourage beneficial soil organisms. This all leads to a healthy and productive root system, critical to plant survival. Our arborist technicians utilize pneumatic technology and specialized air tools to break apart and renovate the soil. The compressed air is not detrimental to existing root systems, utilities or other in ground infrastructure (sprinkler lines, lighting wires etc.).

Cohen & Master’s custom compost is introduced into the soil at depth during the soil renovation process. Our hand blended compost is formulated with humates, volcanic minerals, pH adjusters and other organic material. This compost stimulates biology, improves disease resistance, maintains open pore spaces and creates an ideal environment for healthy root development.

Through these specialized soil treatments address the critical part of the plant: the roots. Give your plants the opportunity to thrive!

Richard discusses Soil Care Cohen and Master arborist’s strives to understand how the growing systems in your yard functions so that we can custom design a program for you.


Aeration tubes promote easier air and gas exchange to the root system of the tree, which promotes healthier root development.

The aeration tubes allow for active convection to take place. This means at nighttime when the temperatures drop, since cooler air is heavier, the aeration tubes convection cap is pulling the cool air down and then forcing the warmer out. This active exchange of oxygen is critical to the tree’s root zone.

They conserve water by allowing direct watering to the roots, eliminating runoff caused by conventional irrigation or sprinklers. These tubes also collect natural rain and any runoff from storms directing it directly into the tubes down to the root zone.

The aeration tubes can be installed when planting new trees, they help reduce shock and stress caused by the transplanting. They also help establish the trees zone quicker and will help promote deeper root growth.

They can also be installed in areas with limited soft scape – like patios with interlock.

Soil Specialist Richard Eaton discusses Soil AerationTubes and their benefits.


Fertilizing trees and shrubs is an important part of your tree and shrub care that is often overlooked or applied incorrectly.

A properly applied deep root feed will increase strength and encourage growth from root to tip.

At Cohen and Master, our fertilizer is designed specifically for Toronto’s alkaline clay soil. It combines essential macronutrients with bio-stimulants and live biology. We inject slow-release, low-salt fertilizer (along with organic ingredients to improve the overall health of the soil ecosystem) into the ground around your tree.

This will help your plants fend off the harsh elements of the urban environment such as: Lack of proper nutrients, Soil compaction and Disease or pest infestations.

Ask us about FERTILIZERS!
  • Promote green vigorous growth

  • Stimulate healthy root growth
  • Increase disease resistance
  • Add important nutrients back into the soil
  • Aerate the soil to help with compaction


Trees are living organisms that can be affected by insects and disease – such as Emerald Ash Borer (EAB) or Dutch Elm Disease.
If left untreated, repeated infestations can lead to a tree’s total decline.

When caring for the health of a tree, many factors must be considered, and solutions require a well rounded approach.

A Cohen & Master arborist should be consulted if your trees and shrubs are showing symptoms of decline.

Our tree experts understand that a change in leaf colour, early leaf drop or branch die-back could all be indications of a greater problem.

Cohen & Master’s bio-treatments are environmentally friendly and approved in the province of Ontario.