Topic: Tree Care

Why use Dormant Oils?

tree health

Dormant oils have been used since the late 1800s to control a wide range of insect pests on fruit and shade trees. They have a faithful following because they are safe to apply and degrade quickly in the environment. Additionally, they are valuable because of their compatibility with many other IPM controls and particularly because they are less harmful, than other pesticides, to non-target beneficial insects. Dormant oils have many different names. Some are called superior oils, supreme oils, petroleum oils or horticultural oils. All are a light-weight oil that is pale amber in colour with little odour.

Dormant oils are used to control overwintering and exposed soft-bodied insects and eggs of aphids, mealybugs, mites and scales that attack many different species such as dwarf Alberta spruce, roses, junipers, Mugho pines, magnolia, lilacs and euonymus.

The low toxicity of this product makes it safe to use for humans and most wildlife

The window for dormant oil spraying is in early spring once temperatures rise above freezing and prior to bud break or late fall after leaf drop. Some products can also be used in the summer during active growth.

Tree Fertilization

Fertilization is performed for a number of reasons, which include:
• to help replenish sterile urban soils that do not get the opportunity for nutrient recycling
• to help strengthen diseased trees
• to aid the establishment of young trees
• to provide nutrients where poor soil conditions exist
• to provide nutrients for trees growing in adverse conditions 
• to assist older trees• to increase the rate of growth


The residual quality of our fertilizer provides nutrient release throughout two seasons. This product also contains a complete package of secondary micro nutrients for healthy tree growth. We compliment our fertilizer with Mycorrhizae beneficial fungi. The fungi colonize the roots and help them to sequester water and nutrients from the soil. Some trees may have special needs that would require a complement of additional products such as chelated iron or soil acidifiers. These would be applied where needed.

Monitoring the Health of your Trees

monitoring the health of your trees

Take the time to look at your trees close up and from far away.  Look at them as individuals and as a group.  Look up and look down.  If you see anything that causes concern call your arborist at Four Seasons Tree Care.

The best way to a healthy landscape is to be proactive and preventative. Monitoring on a regular basis throughout the growing season by a knowledgeable, experienced Arborist with a keen eye will help to minimize potential threats to the health and safety of your trees and shrubs.  Trees that are stressed or in decline or perhaps have died are usually suffering from a combination of factors.  Insects and diseases are often secondary, as they prefer to attack weakened trees. 

A Plant Health Care Program that includes monitoring with treatments as required can be set up through Four Seasons Tree Care, ensuring that a qualified Arborist is on your property several times throughout the growing season.  This helps to keep insects or diseases at a tolerable level and reduce the use of pesticides.  Consideration is given to several control options using an Integrated Pest Management system to develop, restore, preserve or augment natural checks and balances.   Recognizing beneficial pest organisms is a crucial element in this process. Early and correct diagnosis of a disorder can make the difference between a healthy landscape and a happy homeowner or a dead tree.

Environmental stressors and climatic conditions can weaken trees and shrubs making them more susceptible to insect and disease attack.  Not all disorders are infectious.  Physiological disorders account for a large percentage of declining trees.  The Arborists at Four Seasons Tree Care will make recommendations to improve the site conditions for your trees and shrubs. These options may include soil amendments, fertilizing, pruning, planting the right tree in the right place and sometimes even removals.

Improving the overall health and safety of your trees and shrubs is a top priority for our Arborists.