Do Pepper Seedlings Need Light?

Light exposure is essential to grow peppers (Capsicum spp.) successfully. Neglecting to expose pepper seedlings to sufficient light can result in spindly, weak and tall plants that won't thrive in the garden. Peppers are warm-season vegetables, and the seeds need high temperatures to sprout, which is why they're usually started indoors about eight weeks before the average last spring frost date. This gives you the opportunity to make sure the young plants get all the light they need.

When you start pepper seeds, light is not an essential factor, because the seed will also germinate in the dark. Sow the seeds 1/4 inch deep in a seed-starting flat that's filled up to 1 inch from the top with moistened sterile seed-starting mix. Then cover the tray with plastic wrap to create a greenhouse-like effect, and place it on a heat mat set to 80 degrees Fahrenheit. Keep the medium moist during the germination period and expect the seeds to sprout within five to 10 days.

Light exposure becomes essential immediately after the seeds sprout. Remove the plastic wrap and the heat mat and expose the tray to light. If you have a sunny, south-facing window, place the tray in the window and rotate it periodically so the emerging plants grow upright and don't lean to one side. Monitor the seedlings closely, because if they appear pale, spindly or weak, it might indicate they're not happy with the amount of light they're receiving. A supplemental light source might be required.

If you don't have a sunny window, or if your seedlings appear weak, use 40-watt fluorescent tubes to provide the seedlings with enough light. Suspend the tubes above the seedlings at a distance of about 2 inches. Leave the light on for 12 to 16 hours every day, and as the seedlings grow, move the fluorescent tubes up so they're always 2 inches above the plants. When the seedlings are 2 to 3 inches tall, transplant them to individual containers and continue the light exposure.

Before transplanting the seedlings in the garden, harden them off to prevent transplant shock, which occurs when seedlings are suddenly exposed to the outdoor elements. When night temperatures are 55 degrees Fahrenheit, place the seedlings in a sheltered area outside for two hours and, over a one-week period, gradually increase their exposure to the elements and lengthen the duration that they're outside until they're able to stay outside the entire day. Then, transplant them in a sunny area of the garden, late in the afternoon or on a cloudy day.