Water is key to the health and life of trees, but knowing  just how much, how often and when to water can get a little tricky. Some of the factors to consider are weather conditions, soil type and whether your trees are newly planted or well established.

When to Water Your Trees

First of all, to prevent evaporation and stress, avoid watering trees in the hottest part of the day, instead water early in the morning and in the evening.

Secondly, a simple test to determine the need for watering can be done by inserting a trowel into the soil about 20 or 25 cm. If the soil feels damp, it is unlikely to need water, but if it is dry, then watering is probably required.

watering a young treeFinally, check for signs of stress or drought, which include:

  • wilted leaves
  • little growth
  • curled or rolled leaves
  • colour change

Generally, trees need water corresponding to about  25 mm of rain per week from June to September. However, avoid over-watering which can also cause stress.

How to Water a Tree Properly

The important thing to remember when watering your trees is to make sure the water is delivered slowly and heavily, so the roots can absorb the water, otherwise it encourages shallow root growth. Shallow roots cannot tolerate drought.

Water around the tree’s drip line (circle on the ground marking the edge of the tree canopy), rather than just around the trunk.

Too much water and roots will drown, too little and they will dry up and die.

Heavy clay soil does not drain well and needs less frequent, but heavier watering.  Lighter, sandy soils need less water applied at a time, but more frequently.

Do Newly Planted Trees Need More Water?

sprinkler on lawn watering treesYes indeed they do! New trees need water to survive and thrive. 

Transplanted trees need water immediately after they have been planted and on a frequent and regular basis after that. Water helps newly planted trees establish roots and recover from being transplanted. These trees should be watered well at least once or twice a week, either with an irrigation bag or a soaker hose. This needs to continue throughout the growing season and for the first 1 or 2 years.

Watering and Established Trees

As a general rule, established trees do not need watering because their roots are wide and deep. Only when it is especially dry and hot or windy, they may need water just to keep healthy and maintain strength and avoid stress. Water helps reduce the risk of disease in trees or the invasion of insects, pests, etc.

Remember, a tree is an investment and a healthy tree is better able to withstand insects, pests and diseases.

Local weather conditions, your soil type and the age of your trees are all factors that determine the amount and frequency of watering needed. The best thing you can do for your trees is to provide the right amount of water at the right time. This will ensure that you grow and maintain vigorous and beautiful trees that benefit you and the environment.

Rely on Ottawa’s Tree Pros at Croft Tree Experts

If you have questions, contact the certified arborists at Croft Tree Experts. We specialize in tree assessment and advice, as well as tree pruning, tree removal, hedges and much more.