Growing roses in soilless culture (cinder + coarse sand) requires a complete hydroponic fertilizer—standard garden fertilizers lack essential trace elements and can burn.
| Element | % |
|---|
| Total Nitrogen | 7% |
| Phosphorus (P₂O₅) | 9% |
| Potassium (K₂O) | 5% |
| Calcium (Ca) | 2% |
| Magnesium (Mg) | 0.5% |
| Sulfur (S) | 0.05% |
| Iron (Fe) | 0.1% |
| Manganese (Mn) | 0.05% |
| Zinc (Zn) | 0.05% |
| Copper (Cu) | 0.05% |
| Boron (B) | 0.02% |
| Molybdenum (Mo) | 0.0009% |
| Cobalt (Co) | 0.0015% |
| Nickel (Ni) | 0.05% |
| Chlorine (Cl) | 0.1% |
| Sodium (Na) | 0.1% |
Look for a 7-9-5 hydroponic formula with these micros. Foliar spray first for quick uptake.
Blind Shoots (No Flower Bud)
Causes: insufficient light (<6 hrs direct sun), nutrient imbalance, temperature extremes, or genetic tendency. Detailed article here.
Gibberellic Acid (GA₃) – Use With Caution
GA₃ forces flowering but is a potent hormone. Wrong dose/timing causes deformities. Only for commercial timing (e.g., holiday crops). Your roses likely need better nutrition, not hormones.
Bacterial Issues in Soilless Media
Drench with 1 tsp 5% bleach per quart water. Wait 2 days before fertilizing (chlorine dissipates).
Black Spot Prevention
Spray fungicide at leaf-out, monthly. Once spores settle, it's too late.
Copyright © www.100flowers.win Botanic Garden All Rights Reserved
