Pick: indoor fertigation schedule
Pick the indoor schedule if you want a repeatable fertilizer plan. You mix a stock tank, set pH, set EC, and water to runoff. The schedule changes with growth stage, not with rain. Indoor containers dry on a known cycle. You can measure the result.
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Use this pick for coco coir, peat, or rockwool. Soil indoors works too. The numbers below assume a soilless mix and a drain-to-waste system.
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Indoor schedule
- Seedling: EC 0.6 to 1.0, pH 5.8 to 6.0, water at 10% to 20% runoff.
- Vegetative: EC 1.2 to 1.8, pH 5.8 to 6.2, feed at each watering.
- Flower week 1 to 3: EC 1.6 to 2.0, keep N at 100 to 150 ppm.
- Flower week 4 to 7: EC 1.8 to 2.4, raise P and K, keep Ca and Mg.
- Final 7 to 10 days: EC 0.4 to 0.8 or plain water. Flush evidence is limited. Runoff EC tells you salt buildup.
Check runoff EC each week. If runoff EC is more than 0.5 above input, cut feed or increase runoff. Check pH daily. Adjust with nitric or phosphoric acid. Do not guess.
Outdoor schedule option
Outdoor plants use field soil, containers, or raised beds. Rain, temperature, and soil biology change the plan. A soil test is the first step. Test pH, organic matter, phosphorus, potassium, calcium, and magnesium. Apply lime or sulfur before planting if pH is off target. Target pH 6.0 to 6.8 for soil.
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Outdoor steps
- Preplant: mix compost and a slow-release P and K source into the top 6 to 8 inches.
- Vegetative: side-dress nitrogen every 3 to 4 weeks. Use 0.5 to 1 lb N per 1,000 sq ft per application. Split total N across the season.
- Flower: shift to lower N and higher P and K. Apply potassium sulfate or compost at first flower.
- Rain: cover beds or apply nitrate in small split doses. Nitrate leaches. Ammonium and organic N move less.
- Mulch: straw or wood chips hold moisture and reduce splash.
Outdoor containers dry faster than field soil. Water and feed on a 2 to 3 day check in heat. Do not follow a calendar. Lift the pot or use a moisture meter.
Outdoor vs indoor at a glance
- Control: indoor wins. pH and EC are measured at each watering.
- Cost: outdoor wins on fertilizer volume. Field soil holds nutrients.
- Risk: outdoor rain leaches N. Indoor salt buildup raises EC.
- Convenience: indoor uses a stock tank and timer. Outdoor uses a soil test and split applications.
Options after the pick
Pick indoor if you want a schedule you can log and repeat. Pick outdoor if you have a soil test and can split N. A hybrid plan works for greenhouse plants in containers. Use the indoor pH and EC targets. Add a soil test for the media. Cover the pots in heavy rain.