pine needle mulch

Asked October 8, 2018, 2:11 PM EDT

We have 3 white pine trees and will have bushels of shedded pine needles soon. Can we use them for mulch on our gardens? Or will they be too acidic. We've always put them in yard waste, and it seems such a waste. Thank you for your help. Annet

New Castle County Delaware

1 Response

I will start out by saying that any organic mulch is good for the garden. The Washington State University indicates there is little evidence to support the myth that pine-needles acidify the soil when used as mulch in the garden. The assumption comes from the observation that there are usually no plants growing in the forest among pine needles. In truth the dense root network is the culprit not the pH.

Pine needles are good for annual flowers, snapdragons, zinnias and marigolds especially. Many vegetables and herbs grow well in acid-rich soil conditions. Vegetables prefer a soil pH level of 6.5 to 7 and your pine needles will help create the proper pH. Also, many berry bushes like acidic conditions raspberry, blueberries and strawberries benefit from the increased porosity when using such mulches.

Major benefit of pine mulch is that it is a FREE (in your case) organic mulch that will help break down the soil. They break down slowly, so you use about and inch to an inch and a half each year. Although it doesn’t add any nutrients to the soil. As it decomposes it increases the soil porosity allowing water and oxygen to reach the roots, and doesn’t blow away.

To check the pH of your garden soil have a soil test completed by your local University Extension office.