Plymouth: 763-559-4016
Hutchinson: 320-587-4664

Fertilizing Trees and Shrubs

Dundee Fact Sheets

Fertilizing Trees and Shrubs                 Print This Sheet

Red Oak Tree

Fertilizing trees and shrubs properly results in faster growth, more colorful foliage, and greater production of fruit and flowers. A plant that is well cared for is more likely to resist insect and disease problems.

At planting time, do not apply too much fertilizer. Instead, use a root stimulator.

For established trees and shrubs, the primary need is for nitrogen. Nitrogen contributes to the plant’s growth and foliage color. The best time to fertilize is in early spring or in the fall, after the plant has gone dormant. Do not fertilize late summer to early fall.

Fertilizer can be applied on the surface or directly to the roots. For surface application, use a water soluble fertilizer (such as Schultz Expert Gardener plant foods or Miracle-Gro) applied directly to the foliage and root zone. For root zone application, use granular fertilizer. For most shrubs, the root zone that absorbs nutrients is 1’-3’ from the base of the plant. For trees, this area is just beyond the canopy (the area covered by the widest spread of the branches) and inward about 1/3 of the way to the main trunk.

To apply fertilizer directly to the roots, use one of three types of fertilizer:

GRANULAR...Apply a 10% nitrogen fertilizer at the rate of 1 lb. per 1” of trunk diameter.

WATER SOLUBLE...Applied through a root feeder attached to a hose.

SPIKES...Follow specific package directions for application rates. Space the fertilizer
evenly across the root zone with the holes spaced 18”-24” apart and 12”-15”
deep. Water the root zone one day before application to make it easier to dig holes.

Water soluble fertilizers will be taken up more rapidly by the plant but will have a shorter effective period than granular types.

Always sweep up any granular fertilizer that gets on sidewalks, driveways, patios, and other hard surfaces. Fertilizer that gets swept into storm sewers is a contributing source of phosphorous which turns lakes green.


Click Fertilizing Trees and Shrubs Fact Sheet for a printable version of this page.

The printable page of this Fact Sheet is a .pdf file that you can browse or print. You will need the Adobe reader to access this file. It's available free at

Bookmark and Share