If you’re reading this post, its likely that you’ve successfully started your plants from seed. Congratulations! Or perhaps some plants may have ‘followed you home’ from the garden center.
If you are growing seedlings under grow-lights, the tops of the seedlings should be about 1” from the fluorescent tubes. Don’t allow the seedlings to grow into the lights as the leaves may burn. Seedlings don’t need to be as close to the lights if you are using LED lights. Lights should be on for about 16 hours a day for most crops. If you are growing spinach under lights however, don’t give them more than 10 or 11 hours of light because they will be stimulated to ‘bolt’ (flower), because that much light simulates the long days of summer, when bolting usually happens. When spinach bolts, it becomes tough and bitter tasting. Monitor your seedlings carefully as they sprout to make sure they don’t dry out.
Conversely, also make sure they are not sitting in water, as this is a great environment for damping off diseases such as pythium or phytophthora to develop. Damping off symptoms include the seedling stem withering at the base so the seedling falls over and dies due to the rotted roots below. Start fertilizing your seedlings with a dilute water-soluble fertilizer about every other week once they get to be about one inch in height. The roots should be established enough by then to be able to take up the fertilizer well. When it gets close to the time you can plant outside, (whenever your last frost date is for your area) start to acclimate the plants by putting them outside for a while each day, starting in a semi-shaded place and gradually moving them to more sun. This process should take one to two weeks.