We use 1k watt Gavita DE lights, but CFLs can work in addition to natural sunlight. We recommend a minimum of ten 1000watt lights in a standard 30x100 ft greenhouse. We turn on our lights for a few hours in the morning and again for a few hours in the evening, and sometimes leave them on all day when cloud cover is significant. The goal is to maintain at least 16 hours light.
Keep temperatures between 75-85°F for fastest and highest germination rates; seeds will not consistently germinate until soil temperatures reach 68°F.
Plant seeds ¼” deep in soil and cover lightly. We use 72 or 50-cell vegetable starter trays that are about 3” deep. Water trays gently, soil should be moist but not wet. Overwatering can cause seeds to rot, while under-watering will prevent the seeds from sprouting. Remain vigilant in maintaining proper moisture until seeds germinate, as this is the most critical period of the entire season.
Seeds should sprout in 5-10 days, under ideal environmental conditions, with a 90-95% germination rate. Keep in mind they will not begin to sprout until soil temperatures warm, so if conditions are less than ideal it can take longer and result in sporadic germination. We suggest waiting 14-20 days after soil temps have warmed before disposing of any ungerminated seed.
Water plants as necessary and be gentle on fresh seedlings as stalks are developing. Misting the soil is the safest means of watering. Once seedlings have emerged, temperatures can be lowered to 60-80°F. For fastest vegetative growth maintain around 60-70% relative humidity.
Do not expose young seedlings to freezing or above 100°F temperatures. As plants grow, trays may need to be watered multiple times a day to prevent roots from drying out. Check them multiple times a day, especially during heat waves.
We recommend transplanting when plant roots have reached the bottom of the tray, and starts are between 6"-8” tall. If leaves begin to yellow prior to transplanting, you may want to foliar feed with a nitrogen fertilizer.
For more comprehensive cultivation information please download our complete guide HERE.