• Catastrophic weather for our Trees and Shrubs

In Canada we all eagerly await the arrival of warmer weather. The high temperatures become tolerable when we think back to the chill of winter months. However, sunny days come at a cost and the lack of precipitation this spring and now into summer has begun to have catastrophic effects on our urban landscape.

Jeff Coulson, Environment Canada meteorologist, stated that this has been the driest May since 2005 and the driest June since 1991. Soils have become parched. Devoid of any moisture, the soil loses its ability to absorb what little rain might fall as water runs off across dry surfaces. These conditions can spell disaster for even the hardiest of woody plants. Water is vital for plant survival and, without it, a host of problems begin to show in our trees.

Our field Arborists are observing the negative effects of this drought on a daily basis:

  • Leaf wilting and crown die-back.
  • Small, stunted foliage.
  • Decreased resistance to pests and disease.
  • Structural weakening and a greater vulnerability to branch drop.
  • Weakened root structures.
  • Total collapse of newly installed plants.

Dry weather places extreme stress on our urban forest. This stress will compound existing issues and greatly weaken our woody plants. Sometimes these effects are irreversible and will have dire long-term consequences to the plant.

What can be done to nurse our trees and shrubs through this difficult time?

  • Yes, irrigation is vital but beware: Typical irrigation equipment, automated watering times and pre-programmed watering frequency will not deliver the kind of deep, slow watering that your woody plants require at this time. What is good for your lawns and flowers is not necessarily beneficial for your trees and shrubs. Consult with your Arborist on suggestions for modifying your watering system.


  • Improve the soil. The already poor urban soils have become even worse, repelling water, limiting root development and contributing to tree instability. Proper soil care for trees and shrubs is executed by an Arborist and involves the process of de-compacting and loosening the soil with compressed air from an Air Spade tool. Then, vital compost material with biological activity, pH balancers and important nutrients are introduced at depth to the existing soil. Available water can now penetrate easily into the soil, feeding the root system of the tree and allowing for the uptake of nutrients from the improved soil. This can be done aggressively in extreme cases or non-obtrusively within manicured landscaped environments. Tree roots remain intact and will immediately thrive under the new soil conditions.


  • Add beneficial bio-stimulants to the roots and the foliage. Humic acid based bio-stimulants are hugely beneficial for woody plants. These mixes promote hormonal activity within the plants, which will increase drought tolerance. Bio-stimulants are an antioxidant and will neutralize oxidizing agents within the plant that would otherwise damage plant cells. These liquids also make valuable micronutrients available to the plant. While plentiful within the soil, these micronutrients would remain locked up and unavailable to the plant without the aid of a bio-stimulant. ArborGain is a specialized bio-stimulant developed by arborists, containing humates, sea kelp and microbial food sources. By applying the product to the root zone and foliage of the plant, stress relief and drought protection is provided.


  • Install specialized aeration and watering tubes for woody plants. On-going plant research has uncovered the value of introducing permanent aeration tubes into the soils around trees and shrubs within the urban environment. These devices allow for active gas exchange into the soil, vital for a plant’s survival. These tubes also serve as an outstanding watering port for the roots of the tree. Even the driest soils with limited surface area can now have large amounts of water and other valuable liquids introduced to the roots of your trees and shrubs at depth. Proper soil saturation can be achieved quickly and efficiently. Any available rainwater is far more easily captured within the root zone of the tree. These devices should be selected and installed by an arborist for maximum benefit to the plant and to ensure the roots are not damaged during the installation process.


Doing nothing for our trees and shrubs during this period of dry weather will result in plant stress, plant damage and even plant loss. This can be catastrophic for our individual landscapes, the entire community and the urban forest as a whole. Cities have never been an easy place for trees. Now is the time for us to provide additional support for our green spaces in order to survive the upcoming months and ensure a healthy and vigorous future for our woody plants.


Consult with your Arborist today!
Give us a call – 416-932-0622 


Tait Sala