Seedling Fertilization: Rates, Timing, and Slow-Release Options

Less Is More for Seedlings

Puckering leaves indicate over-fertilization. At 100 ppm (1/2 tsp 15-30-15/gal), you're likely too strong for soilless mix.

Revised Seedling Protocol

• Wait 2-3 weeks after germination – soilless mix has starter nutrients.
• Use Peters 20-20-20 at 1/4 tsp/gal every other week.
• Watch foliage color – green without yellowing is ideal.
• Keep fertilizer off leaves – prevents burn.

Dahlias & Outdoor Annuals

Same dilute regimen for indoor dahlias. Outdoors, prefer slow-release: Osmocote 14-14-14 monthly or Espoma Plant-tone/Garden-tone. Slow-release provides steady nutrition without weekly liquid applications.

Nitrogen Reality Check

Osmocote's 14% N releases slowly – not equivalent to low-N fertilizer. True low-N formulas (5-10-10) are hard to find; tomato fertilizer (7-10-12) works for flowering annuals. Use existing 15-30-15 at 1/4 tsp/gal until replaced.