Tips on How to Water Trees & Shrubs
Updated: Aug 3, 2019
Did you know that trees, shrubs, and lawn grass have different watering and fertilization needs?
A question we're asked often is "How do I water my trees?"
Always water trees and shrubs slowly, less often.
The majority of trees’ roots are typically in the 6-12 inch range, below ground level. Tree roots spread far past the leafy canopy. (It’s a misconception that trees have deep roots directly underneath the trunk and crown.) When you set out drip irrigation, soaker hose, etc. this slow watering encourages a deeper saturation of water that reaches the appropriate depth for tree roots.
Never water trees and shrubs quickly, and often.
Watering fast and often encourages surface rooting and future tree health problems. When you water quickly, only the top inch or two gets saturated with water. Water runoff (AWAY from your tree!) is also common when lots of water comes out quickly and wastes valuable resources, including your money.
Examples of what to do and what not to do when watering your trees and shrubs
Helpful: Some plants and trees need more water than others, but setting a weekly watering day is helpful. When it hasn’t rained and your moisture meter measurement says the ground is dry, it’s time to water. Watering less often, but for a longer amount of time during watering encourages appropriate root growth.
Harmful: Holding a hose with spray nozzle and giving your tree a quick spritz to wet the top layer of ground causes roots to grow toward the water only found at the surface. Roots need to stay under ~85 degrees in order to grow and operate. Surface roots get too hot to function properly.
What to Use to Water Your Trees and Shrubs:
*The #1 tool to have is a soil moisture meter, find out why it’s a good tool for watering.
Best – Watering close to ground level with soaker hoses or drip irrigation soaks water into the soil slowly over time. This more evenly distributes water throughout the root system and keeps soil consistently moist over longer periods of time. These can hook into your other yard irrigation, or stay around your trees and shrubs, and be connected manually with a regular hose when needed.
Other options can have their drawbacks – If you only have a regular hose with or without spray nozzle, you can turn your water on slow and leave it underneath the tree’s canopy. Move it to a different spot underneath the tree’s canopy every few minutes until the whole area has been watered to appropriate depth. As you can see, this can take a lot of your time! It’s best to buy a soaker hose – it’s worth the investment!
Misting, oscillating, or rotating sprinklers commonly used for grass can cause tree health problems if misdirected. Larger droplets falling to the ground can cause soil compaction, and any water hitting the tree’s leaves or trunk can cause health problems (fungus, mold, rot, etc). Plus you’ll end up with lots of water loss to evaporation!
We hope these tips help with watering and keeping your trees and shrubs healthy. If you'd like more information or for our ISA Certified Arborist to visit your site, contact us today.