Keeping Oregon oaks healthy

Asked April 24, 2017, 4:53 PM EDT

I have about a dozen Oregon white oaks in my half-acre yard. They are glorious old ones that are more than 50 feet high. On a tree trimmer's advice, over the winter I left the oak leaves on the ground around the trees, in beds where I have ferns, rhodies, azaleas, etc. I'm keeping the leaves off the grass. But now that it's spring, should I get the leaves out of the beds? I wonder whether they will hurt the bushes. Still, my #1 concern is to keep the oaks healthy.

Benton County Oregon urban forestry oaks horticulture

1 Response

Sounds like you are using the leaves as mulch in the beds? Mulch will help the soil retain moisture as we move into our dry summer period. I don't necessarily see any problem with leaving the mulch in place. Depending on how long the soil remains moist you may need to adjust your irrigation schedule. Here is an OSU Extension publication called "Mulching Woody Ornamentals with Organic Materials" which has many more details on mulching.
Also happy to look at photos of your garden to give you a more personalized answer. You can attach as a response here or feel free to get in touch with the OSU Extension Benton County to chat with a Master Gardener volunteer.
Thanks for using Ask An Expert!