How to Grow Spinach Under Lights
- 1). Place the spinach seeds in a plastic bag and keep them in the refrigerator for two weeks before planting. Spinach seeds require a short cold period to germinate properly.
- 2). Fill 3-inch seedling pots with a quality potting mix. Sow one to two seeds in each pot to a ½ inch depth. Mist the soil with water until it is evenly moist then cover the top of the pot with plastic wrap.
- 3). Set the seedling pots in a warm room to germinate. Germination takes up to seven days. Remove the plastic once sprouts appear.
- 4). Set the seedlings under the grow lights so the tops of the plants are 6 inches from the light. Leave the light on for 14 to 16 hours a day.
- 5). Water the seedlings as needed, keeping the soil moist but not soggy. Adjust the height of the grow lights as the plants grow to maintain the 6-inch distance.
- 6). Transplant the seedlings to 10-inch pots once they develop their third set of leaves. Plant the spinach to the same depth in the new pot that it was in the old pot.
- 7). Fertilize the spinach once a week with a liquid soluble fertilizer, following package instructions for exact application rates. Water with clear water as needed between fertilization.
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