Fertilizing Shrubs: Timing, Rates, and Application Tips

Easy to forget shrubs, perennials, annuals need regular feeding during growing season. If fertilized only at planting, plants starve six weeks later. Response: few flowers, weak growth, more susceptibility to insects and disease.

Two ways to fertilize: if watering regularly, use granular 10-10-10, 1 pint per 100 sq ft of bed. If not watered regularly, use water-soluble (MiracleGro, Peters) per label directions.

Fertilize two or three times yearly: usually March, May, July. Fertilizing won't fix other problems: constantly moist/dry soil, compacted, overly acid/alkaline. Check site, correct problems first. Older plants or where more growth not desired may get only March application.

Fertilizer numbers = percent nutrient. Example: 12-4-8 = 12% nitrogen, 4% phosphorous, 8% potassium = complete fertilizer. Slow-release more expensive but less garden time. Always follow package directions.

Rate depends on numbers. 12-4-8 or 16-4-8 applied to 3-foot shrub at 6 tsp or 2 tbsp. Shrub <12 inches gets 1 tsp only.

8% or 10% ratio (8-8-8, 10-10-10) applied at 1 level tbsp per foot of height. Shrub <12 inches gets heaping tsp.

CAUTION: Pile of fertilizer in one spot dissolves and burns roots. Sprinkle lightly around plant.

• Stay 6 inches from main stems
• Distribute granules beyond drip line—roots extend beyond drip line.