Table of Contents
- Understanding Nutrient Basics for Feminized Cannabis
- What You’ll Need — Tools, Media & Prerequisites
- Step-by-Step Feeding Schedule — Seedling to Flower (Numbered Steps)
- Mixing & Delivering Nutrients Correctly
- Diagnosing Nutrient Problems — Troubleshooting Common Issues
- Tips for Success & Pro Tips for Experienced Growers
- Harvest Prep: Flushing and Final Nutrient Adjustments
- Ongoing Record-Keeping, Testing & Scaling Your Feeding Plan
- Conclusion
Understanding Nutrient Basics for Feminized Cannabis
| Nutrient | Primary Function | Deficiency Symptoms | Toxicity/Excess Signs |
|---|---|---|---|
| Nitrogen (N) | Drives leaf and stem growth, chlorophyll production | Older leaf yellowing, slow veg growth | Dark, clawed leaves; nutrient lockout |
| Phosphorus (P) | Root development, flower initiation and maturation | Dark/purple stems, slow flowering, small buds | Leaf bronzing, reduced uptake of Fe/Cu |
| Potassium (K) | Overall vigor, water regulation, bud density | Leaf edge burn, weak stems, poor bud development | Leaf tip burn, reduced Mg uptake |
| Calcium & Magnesium (Ca/Mg) | Cell wall strength (Ca), chlorophyll cofactor (Mg) | Blossom/end rot, interveinal chlorosis | High Ca causes Fe/Zn deficiency; excess Mg rarely toxic |
| Iron (Fe) & Micronutrients | Enzyme cofactors, chlorophyll synthesis, defense | Interveinal yellowing on new growth, poor development | Dark leaf speckling; micronutrient toxicity rare but mobile imbalances occur |
What You’ll Need — Tools, Media & Prerequisites
Step-by-Step Feeding Schedule — Seedling to Flower (Numbered Steps)
| Growth Stage | Weeks | pH (Soil/Coco/Hydro) | EC (mS/cm) Range | NPK Focus |
|---|---|---|---|---|
| Seedling | 1–2 | 6.0–6.5 / 5.8–6.2 / 5.5–6.0 | 0.4–0.8 | Low N, micros |
| Early Vegetative | 2–4 | 6.0–6.8 / 5.8–6.2 / 5.6–6.0 | 0.8–1.2 | Increase N |
| Late Vegetative | 4–8 | 6.2–6.8 / 5.8–6.2 / 5.8–6.0 | 1.0–1.6 | High N, balanced P/K |
| Pre-Flower (Transition) | 1–2 | 6.0–6.6 / 5.8–6.2 / 5.6–6.0 | 1.4–1.8 | Reduce N, raise P/K |
| Flowering | Weeks 3–8+ | 6.0–6.5 / 5.8–6.2 / 5.8–6.0 | 1.6–2.2 | High P/K, Ca/Mg |
| Flush | Last 1–2 | Maintain stable pH | <0.6 | Plain water (remove salts) |
Mixing & Delivering Nutrients Correctly
Diagnosing Nutrient Problems — Troubleshooting Common Issues
| Symptom | Likely Cause | Immediate Fix | Prevention |
|---|---|---|---|
| Yellowing lower leaves | Nitrogen deficiency or natural senescence | Increase N slightly; check EC/pH | Balanced N in veg, staged feeds |
| Leaf tip burn (brown edges) | Salt build-up / high EC | Flush with pH-balanced water | Frequent runoff testing; lower EC |
| Purpling stems or veins | Cold stress or P shortage | Warm root zone; moderate P feed | Maintain temps; stage-appropriate P |
| Slow growth despite feeding | Root health issue or pH lockout | Inspect roots; adjust pH; mild root drench | Root hygiene; correct pH range |
| Blossom deficiencies (powdery, small buds) | Micronutrient or Ca/Mg imbalance | Add chelated micros; supplement Ca/Mg | Complete bloom nutrient program |
Tips for Success & Pro Tips for Experienced Growers
| Supplement | Purpose | When to Use | Dosage Notes |
|---|---|---|---|
| Mycorrhizae / Microbial inoculants | Increase P uptake, root mass | At transplant and every 4–8 weeks | Typical: apply per product label; hobbyists use 1–3 g/root ball or follow liquid rates |
| Silica (Si) | Improve stem strength, stress resistance | Continuous veg → early flower | Typical: 50–150 ppm (e.g., 0.5–2 mL/L depending on product) |
| Cal‑Mag supplement | Prevent Ca/Mg deficiencies with RO/well water | Throughout veg and early flower as needed | Typical: 1–5 mL/L or 1–3 tsp/gal; reduce if tap water already contains Ca/Mg |
| Bloom PK boosters | Drive flower size and resin production | Week 3–6 of flower (mid-flower window) | Typical: start at 25–50% label strength, ramp to manufacturer recommendation if plants tolerate |
| Foliar micronutrient sprays | Quick correction of micronutrient deficiencies | As corrective sprays in veg and early flower | Typical: dilute to 0.1–0.2% solution; spray in low light, avoid bud contact |
Harvest Prep: Flushing and Final Nutrient Adjustments
📥 Download: Feminized Cannabis Nutrient Management Checklist (PDF)
Ongoing Record-Keeping, Testing & Scaling Your Feeding Plan
| Grow Size | Reservoir Volume | Mix Frequency | Monitoring Frequency | Special Considerations |
|---|---|---|---|---|
| Small (1–10) | 10–25 L | Weekly full mix | Daily check (pH/EC) | Manual aeration, simple backups |
| Medium (10–50) | 100–300 L | Refill/top-up every 2–4 days | Twice-daily checks | Larger air pumps, blended dosing |
| Large (>50) | 1,000+ L (or split tanks) | Daily mix or continuous dosing | Continuous sensors, alerts | Redundant aeration, automated dosing |