As an ISA Certified Arborist with a Tree Risk Assessment Qualified, I’m getting lots of questions from Red Wheelbarrow customers and from callers on the Horticulture Hangover radio show about watering trees during this (2023) drought. Here’s an example of an exchange I had with a customer today.
“Dear Colleen, We had a consult with you back in May of this year...we haven't done much beyond doing some rocks for edging yet because of the heat but you mentioned we could send you quick questions...Our trees are looking a bit bleak and need watering beyond the once a week sprinklers we've been doing...can you tell me how much, how often and the method (eg not just doing it at the base I'm guessing further out?)?
Thank you,
Dr. Dry in Austin
My response:
Hi Dr. Dry, can you tell me if you planted the trees and if so how long ago you planted them? If you did plant them do you remember what size container they came in at planting time? If they have been in the ground for less than 5 years, they generally need 15 gallons of water once per week. If they came in a container that is bigger than a 15 gallon container, then give them the same amount as the container they came in. For example if the tree came in a 45 gallon pot, then the tree needs 45 gallons of water once per week. Treegators are wonderful for trees that were planted less than 5 yrs ago.
If the trees were planted more than 5 years ago then watering can be a challenge. Water under the “drip line” of the tree. The “drip line” is at the tips of the branches, far from the trunk. Let the water soak in slowly. For my mature trees that are more than 5 years in the ground, I like to use about 15 gallons of water in 4 spots (N,S,E,W) around the tree’s drip line once per week. Get some 5 gallon buckets a drill small holes in the bottom to let the water drain out slowly. That way you know if you fill the bucket 3 times it’s about 15 gallons. This will deliver some water more deeply into the soil than your irrigation system. The tree roots are a little deeper than the other plants in general.
This is a good video to help too:
https://youtu.be/bHsNwpPzK2U?si=WkdXLAiCSFNiH40i
Hope that helps,
Colleen