Watering Drought Stressed Trees

The Twin Cities are experiencing a fifth year of drought conditions. That means our trees have been receiving less than adequate water for five straight years. Five years of significant summer drought conditions will weaken even the hardiest of trees. Without enough water, trees are unable to create new growth. When this happens, root development is reduced and wound formation restricted. As trees reach this stage, they start to shut down and become targets for diseases and insects that can kill them.

So what can a homeowner do? Water your trees! All of your trees, including the big ones! Even mature trees need watering. Over the last decade significant changes in climate patterns are impacting entire ecosystems. Our urban landscapes are not immune to these changes. In fact, trees in urban areas are more prone to drought damage and death than natural stands of trees.

The City of Saint Paul’s Forestry staff
would like to ask people to water their trees [watch their video]

Recommended Watering Techniques

There are two soaking techniques that are recommended when watering with a hose. The first method is to use one of those nifty soaker hoses. Wrap the hose around the base of the tree at least 1-2 feet from the trunk. Turn the water on in the morning when you leave for work and turn it off when you get home.

The other method is to turn your hose on to a trickle. A trickle is more than a drip and less than a gurgle. Visually divide the area around your tree into 4 sections. Place the hose about 2-3 feet from the trunk in section one and let the water soak into the ground for about two hours, move the hose to another section until you have fully watered all four quadrants over the period of a day.

Watering Trees Impacted by Drought Conditions

If you have in-ground irrigation, let it run an extra hour in the zones where you have trees and shrubs. This will allow the water to penetrate through the turf roots and thatch and allow more water to soak down to the roots of the trees.

All methods should be done once a week, through the end of September, while we are experiencing drought conditions.

Sprinklers are not recommended! Sprinklers work best for watering grass, not trees. By using the soaking techniques you saturate the grass in the spot where the hose is so that the water will move beneath the root zone of the grass and get to the tree roots where it is needed. Trees can die even when the grass is green, because grass is the better competitor for water.

Fertilizing with nitrogen fertilizers is also not recommended. Fertilization can worsen drought conditions by forcing plants, especially trees, to grow despite not having enough water to support that growth. During a drought we want to encourage trees to conserve energy rather than expend it.

The reality is if you don’t water your trees now, you could be giving us a call for removal this winter or next spring. At Rainbow Treecare we have products to help maintain your trees’ health, but most important is the care you provide by proper watering. If you have any questions about watering trees or any other preventive tree care practices, please feel free to call Rainbow Treecare. Our Certified Arborists can help provide the best care for your trees.

Dr. John Lloyd is the Director of Research and Science at Rainbow Treecare. He is committed to the education and improvement of tree health in the Twin Cities.

An integrated approach

When caring for urban trees it is important to make a complete evaluation of all environmental conditions to accurately diagnose all stress factors and prescribe care based on specific circumstances. This prescriptive care will help your tree meet its full potential.