Mostly water, really. Many factors play into the health and vigor of urban trees. Ideally, we select a specimen tree at the nursery that is hardy for our zone, we plant it properly in a perfect location in nutrient rich soil, we fertilize and prune and water at all the right times and the tree lives out it’s glorious life without suffering any stress. Unfortunately this isn’t the way the story usually goes. We live in Southern Alberta for starters and we experience some of the most extreme and unique weather swings in the world. Between chinooks, hard frosts in June, wild winds and increasingly dry growing seasons, our trees have a lot to contend with. Aside from that, we are a growing city and new development in many areas that our precious mature trees call home can wreak havoc on established root systems and canopies, causing long term damage. This is all in addition to the fact that sometimes trees don’t receive a lot of love and can go neglected for period in their lives. They’re quiet beings and they don’t demand a lot so they often get overlooked until something is obviously wrong. They’re pretty self sufficient but urban environments are very different from the natural stands that they’re used to growing in. Environmental stress compounds and susceptibility to insects and pathogens increases and we start to see them struggle.
So what can we do? The best and most important thing that you can do as a homeowner is water your tree properly! And how do you do that, you ask? The key is to make sure that you are watering as deeply into the soil as possible. This is achieved by reducing the intensity and increasing the duration of your watering cycle. This ensures that the water has time to work it’s way down the soil profile which reduces the amount of water lost through evaporation at the surface and encourages the tree to send its feeding roots deeper into the soil where water is available to the tree for longer periods during dry or drought conditions. Sometimes the common tools that we use to water our lawns and flowers are not the best choice for watering trees, often, they put down too much water, too quickly and you will start to see runoff. This often prompts people to stop watering, which won’t result in deep water penetration into the soil. This will provide relief for the short term but won’t help the tree when things start to dry out. Tools such as drip hoses, Tree Gators and the TreeIB irrigation bag help release water slowly, eliminating runoff and allowing time for the water to soak deep into the soil.
Regular deep watering will produce trees that are visibly healthier, more vigorous and more resistant to and more able to withstand other stress factors such as insect infestation, infection by diseases and environmental stresses such as late or early frosts, chinooks and lack of precipitation.
We have agreat article on exactly how and when to water young and Mature trees available here.
