Fertilization Timeline

The fertilization season for winter hardy plants begins in the fall 4-6 weeks after the first killing frost and runs though early to mid spring (or as plants leaf out and begin to grow). Approximately December 1st through March 15th. 

Granular vs. Liquid Fertilizers 

Using a granular or slow release fertilizer will gradually provide the desired nutrients to the plant throughout the season. Granular fertilizers are typically more economical and easier to apply. 

Liquid fertilizers are not generally recommended for trees, shrubs, or perennials no matter what season because they only provide a quick release of energy to the plant. 

Many of the granular fertilizers we carry not only provide long lasting nutrients but also the added benefit of microbial activity, which helps create a healthier soil environment 

Newly Planted Trees, Shrubs, & Vines

Trees and shrubs planted this year will benefit from a light fertilization (1/2 of the recommended dosage) in the fall, as long as you use a granular fertilizer with low nitrogen (6 or lower).

Young, Established Trees 

Trees in the ground 1-10 years benefit from an annual fertilization with a balanced 6-6-6 fertilizer, or higher NPK ration (not to exceed 20-20-20) 

Mature Trees 

Mature trees (in the ground 10+ years) benefit from fertilization every 3-5 years. Certified arborists have the most effective tools to fertilize mature trees. Please consult a Team Member for a certified arborist in our area. 

Perennials & Shrubs 

Similar rules apply when it comes to fertilizing perennials and shrubs in the fall/winter. Use a granular fertilizer and apply it throughout the planting area. We prefer to fertilize perennials and shrubs in February or March before active growth begins. An alternate application schedule is to apply ½ the recommended rate in February, then in June apply another ½ application. 

Ornamental Grasses 

These plants generally do not require fertilization and perform best without them. 

Ground Covers 

Fertilization of ground covers is both site and variety specific. Please consult a Team Member for a recommendation.

Consult a Plant Kingdom Team Member for plants in decline or compromised health due to injury, insects, or disease.