Seedling Additives Reference | Neon Genetics
Jan 2026

Seedling Additives Reference

Evidence-based additives for germination and early-stage development. Ranked by research support and practical value.

Tier 1 — Strong Evidence
Tier 2 — Moderate Evidence
Tier 3 — Context-Dependent

🧪 Tier 1 Additives

Kelp / Seaweed Extract
Tier 1
Mechanism
Natural cytokinins (zeatin), auxins, betaines, and alginates promote cell division during germination
Effect
15-30% faster germination rates; improved root mass; enhanced stress tolerance
Application
1-2 mL/L in germination water; foliar at emergence (0.5-1 mL/L)
Products
Kelpak Sea-Crop Maxicrop
Cold-processed Ascophyllum nodosum extracts preferred. Research: Crouch & van Staden (1993) documented cytokinin activity.
Humic / Fulvic Acids
Tier 1
Mechanism
Chelates micronutrients, improves membrane permeability, hormone-like effects on root development
Effect
Enhanced nutrient uptake efficiency; faster root establishment; improved cation exchange
Application
Fulvic: 0.5-1 mL/L (preferred for seedlings due to lower molecular weight)
Products
BioAg Ful-Power RAW Humic
Use fulvic for seedlings (immediate uptake); humic more effective once roots establish. Research: Canellas et al. (2015) meta-analysis.
Mycorrhizal Inoculants
Tier 1
Mechanism
Glomus species form symbiotic relationships, extending effective root zone via hyphal networks
Effect
20-50% increase in effective root surface area; improved P uptake; drought tolerance
Application
Dust directly on roots at transplant or incorporate into media. Must contact roots.
Products
Great White Dynomyco Mykos
Controlled P levels (110 ppm) favor colonization—high P suppresses mycorrhizal establishment. Best species: G. intraradices, G. mosseae.
Trichoderma Species
Tier 1
Mechanism
Competitive exclusion of pathogens; produces growth-promoting compounds and enzymes
Effect
Disease suppression + 10-15% growth enhancement; improved nutrient solubilization
Application
Incorporate into media or root drench at transplant
Products
RootShield Plus Real Growers Recharge
Works synergistically with mycorrhizae (different ecological niches). Key species: T. harzianum, T. viride.

⚗️ Tier 2 Additives

Silica (Potassium Silicate)
Tier 2
Mechanism
Strengthens cell walls; improves stress tolerance and structural integrity
Effect
Sturdier seedlings; reduced damping-off susceptibility; heat/drought tolerance
Application
0.25-0.5 mL/L potassium silicate. Begin after cotyledon expansion.
Products
AgSil 16H Power Si
Must be added to water FIRST, before other nutrients—precipitates with calcium if mixed incorrectly. Raises pH significantly.
B-Vitamins (Thiamine)
Tier 2
Mechanism
Cofactor in carbohydrate metabolism; potential stress reduction during transplant
Effect
Disputed—some studies show transplant shock reduction; healthy plants synthesize adequate B1
Application
1-10 mg/L if using. Powder form vastly more economical.
Products
Thiamine HCl powder B-Complex powder
Original research was on isolated root cultures, not intact plants. More defensible for cloning than seed starts. Skip B12—plants don't use it.
Enzymatic Treatments
Tier 2
Mechanism
Cellulases and pectinases help break down seed coat; clear dead root matter
Effect
Can improve germination of older or thick-coated seeds
Application
Brief soak (1-4 hours) in enzyme solution
Products
Hygrozyme SLF-100 RAW Enzymes
Reserve for seeds with known germination issues—not necessary for fresh, viable seed.

🔬 Tier 3 Additives

Hydrogen Peroxide (H₂O₂)
Tier 3
Mechanism
Provides supplemental oxygen; surface sterilization of seed coat
Application
1-3% solution for 10-30 minute soak
Can damage embryo at higher concentrations or extended exposure. Useful tool for problematic seeds only.
Gibberellic Acid (GA3)
Tier 3
Mechanism
Breaks seed dormancy; promotes cell elongation
Application
100-500 ppm soak for 12-24 hours
Causes excessive internode stretch if used unnecessarily. Reserve for truly dormant seeds or breeding lines with germination issues.
Chitosan
Tier 3
Mechanism
Elicits plant immune responses; antifungal properties
Application
Seed coating or drench at 0.1-0.5%
Promising but limited cannabis-specific research. May support systemic acquired resistance.

📋 Application Protocol — V1/V2 Timeline

1
Germination
Days 0-3
  • Soak 12-18 hrs in RO water + kelp (1 mL/L)
  • Transfer to paper towel or direct to coco
  • Maintain 80°F, high humidity, darkness
  • Mist with plain RO if surface dries
2
Emergence
Days 3-7
  • Introduce light at 200 PPFD on cotyledon opening
  • Water: RO + kelp (1 mL/L) + fulvic (0.5 mL/L)
  • Apply mycorrhizae/trichoderma if not in media
  • Maintain 75-80°F, 65-70% RH
3
Establishment
Days 7-14
  • Transition to ¼-strength NEON formula
  • Begin silica if desired (add first to water)
  • Increase light to 300-400 PPFD
  • Lower RH to 60-65%

📊 Quick Reference — Rates & Products

Additive Rate Recommended Product Notes
Kelp Extract 1-2 mL/L Kelpak, Sea-Crop Cold-processed preferred
Fulvic Acid 0.5-1 mL/L BioAg Ful-Power Low salt content
Mycorrhizae Per label Great White, Dynomyco Must contact roots
Trichoderma Per label RootShield Plus Pairs well with myco
Silica 0.25-0.5 mL/L AgSil 16H Add to water first
Thiamine (B1) 5-10 mg/L Thiamine HCl powder Optional; low priority