Tips on How to Grow Marigold Seeds:GerminationOptimum conditions for seedling development that begins the day the crop is sown until cotyledon expansion.Expect radicle emergence 3 – 8 days. Cover: Seeds may be covered with a thin layer of medium vermiculite to maintain moisture levels. Media: • pH: 6.2 – 6.5. pH levels <6.0 may induce iron, manganese or sodium toxicity in Marigolds. Symptoms are exhibited on the lower leaves. Marigolds can be used as an indicator plant for low pH. Light: Light is not necessary for germination. If utilizing a chamber, providing a light source of 10 – 100 foot candles will improve germination Dramatically compared to seed germinated in the dark. Moisture: Saturated for days 1 – 3 or until radicle emergence. On days 4 – 7 reduce moisture to moist . Once actively growing, begin alternating between moisture levels wet and medium . Allow media to approach dry before re-saturating to level . Humidity: 100% until radicle emergence then reduce to 40%. Dehumidify: Provide horizontal airflow to aid in drying down the media through evapotranspiration, allowing better penetration of oxygen to the roots. Temperature: 72° – 75°F (22° – 24°C)  Average Daily Temperature (ADT): 67°F (19°C)

Finish Bulking/Flower Initiation – Optimum conditions during the vegetative period, beginning at transplant, needed for the root to reach the edge of the container; AND to make the plant receptive to flower initiation. Media: • pH: 6.2 – 6.5 Marigolds can be used as an indicator plant for low pH conditions. Typical symptoms of low pH <6.0 include yellowing of lower leaves, or browning/burning of leaf edges. Light: Provide 3500 – 4500 foot candles to hasten flower induction. Supplemental lighting under low light conditions at 350 – 450 foot candles will enhance shoot and root growth.

Temperature: 55° – 65°F (13° – 18°C) nights, 65° – 70°F (18° – 23°C) days.

Heat stress will encourage flower heads to be reduced in size. New growth will appear “bleached” when temperatures are too cool in early Spring. Plants will “green up” once night temperatures are increased. Average Daily Temperature 67°F (19°C)

Humidity: 40 – 70%

Dehumidify: Provide horizontal airflow to aid in drying down the media through evapotranspiration, allowing better penetration of oxygen to the roots.

Light: Full sun.

USDA Hardiness Zone: 10.