New fir tree mortality

Asked October 8, 2020, 3:28 PM EDT

Planted a field this spring with a thousand Douglas fir trees. We had a very significant mortality at the upper (drier) end of the field, Before we replant is there a way to prep the field to retain more of the annual moisture that falls here in the Willamette Valley.

Yamhill County Oregon

1 Response

Hi there;

Even in normal years, our summer droughts make seedling establishment challenging. It has been particularly challenging in over the last several years. Add to that site factors such as aspect, soil depth, and competition, and it can be very hard. Dry, shallow soils, especially those on south and west facing slopes can be very hard.

But we cannot affect most of those things. The factor most in our control is cultural practices of site preparation, good planting and handling practice, and weed control. First year weed control essential. Important for several years.

Here are some planting and establishing resources.

The know your forest website has all sorts of information from OSU Extension and other sources. Go to the Learning Library tab, and choose planting trees. Covers seedlings, planting, etc. https://knowyourforest.org/learning-library/planting-trees

Here is a blog post, for reference, giving you information about other weed control resources, including the PNW weed control handbook. If you choose to use herbicides, would be good to look at its safety section.

http://blogs.oregonstate.edu/treetopics/2016/02/23/resources-in-the-fight-against-weeds/

Finally, you need to be aware that Oregon Forest Practices requires notification of your local ODF before doing most forest practices on forest lands. That covers harvest of course, but also using power equipment and spraying. Applies if you are planting forest trees. Not if they are Christmas trees. Check the website for the Oregon Department of Forestry for how to do that. Can also contact your local office.

If after looking through these you still have questions, you can work through my email brad.w-r@oregonstate.edu.

Brad