Knowledgebase

Fertilizing Spruce trees #943668

Asked August 28, 2026, 5:12 PM EDT

We have a large number of spruce trees and sent some soil samples to the U. A report came back with an NPK of 4-0-3. Recommended Nitrogen is 0.07 lbs/100 sq .ft. and Potash of 0.05 lbs/100 sq feet. The trees are NOT showing signs of color change or poor growth, or other changes. Because the soil report shows those numbers, do you feel that fertilizing is necessary or would providing some organic matter to the roots be a better choice. I did ask the soil lab about this and they suggested talking with a tree care advisor. We have had a couple of arborists look at the trees and one says we need a 5 year plan of fertilizing and soil conditioning (which is why we got soil samples). The other says the trees look great and don't need fertilizing. Any advice would be appreciated. Thank you.

Dakota County Minnesota

Expert Response

Susan,

I agree with the arborist that suggested NO fertilizer.

Best,

Shane

An Ask Extension Expert Replied August 28, 2026, 6:26 PM EDT

Loading ...