How do you fertilize spruce trees?

Although there are different ways to fertilize spruce trees, This Old House recommends using a slow-release fertilizer. You will also need a small auger or an iron bar to make holes around the tree.

1. Find the tree's drip line

   Before you fertilize a tree, you need to find its drip line. This is where rain water drips from the outermost canopy of the tree. You will fertilize from this line and out.

2. Dig holes

   Using a small auger, or even an iron bar, dig small holes 12 to 18 inches deep around the drip line of the tree. Make these holes 8 to 12 inches apart.

3. Mix fertilizer

   Use a slow-release fertilizer and mix it with sand, compost, dirt or a combination of these. Talk to your local cooperative extension to find out what fertilizer mix is best for your area.

4. Fill holes

   Take the fertilizer mix and fill the holes around the drip line of the tree. Do this once a year, preferably in the fall, to keep your trees healthy.