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!


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.

We can offer treatments and solutions for many common tree pests and diseases including:
  • Scale
  • Aphids
  • Caterpillars (Gypsy Moth, Tent Caterpillars)
  • Boxwood Leafminer
  • Bleeding Beech Canker
  • Dutch Elm Disease
  • Emerald Ash Borer
Discussion with Tait on the Emerald Ash Borer
Discussion with Tait on Dutch Elm Disease

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