Here is one method you can use to grow Carolina Reaper seeds into big pepper producing plants.
Start with great seeds that will grow true Carolina Reaper peppers from a well-established company. Plant them into a deep 72 cell round insert tray with a solid tray underneath to catch the water.
Fill the cells with seed starter mix and then gently push your fingers into cells. This will remove any large pockets of air and make the soil level with the top of the cells. A great seedling mix is Coast of Maine Organic Products Sprout Island Organic Seed Starter. Water the cells completely until the starter mix is fully saturated. Pour the excess water out of the tray. Place the tray of soil on an electric heating mat today before planting the seeds. Soak the Carolina Reaper seeds overnight in room temperature water.
In the morning place one soaked seed on top of the soil in each cell. Then press each seed into the soil with the large end of a chop stick pushing it down ¼” or less. Cover it up with the surrounding soil and gently tamp it down. You do not want the seed floating up to the top during the first watering. If you are planting 12 seeds, label those cells as Carolina Reaper. At this point, we suggest planting other kinds of pepper seeds in the remaining cells and labeling them also.
Gently water every cell of the tray again even though it is already wet. Hold it under a gentle water faucet and move the tray along to each cell. If a seed floats up, stop and push it into the cell where it belongs. Let the planted cell tray drain into the bottom tray. After a few minutes pour out the excess water.
Put the planted tray back on the heating mat and cover with a clear plastic dome. Place a JumpStart light over the tray and turn it on for 12 hours per day. Keep the light about 4” above the plastic dome. Everyday lift the dome for 10 minutes to exchange air. The soil might stay moist until the first seedling emerges. If the soil does dry on top, water gently with squeeze water bottle. Keep the plastic dome on until there are about 4 little seedlings popping up thru the soil. Then remove it completely. The soil will dry faster now so pay attention.
Without the dome, adjust the grow light to keep it about 5” above the seedlings. It will need to be raised as the seedlings grow. After 6 weeks from the planting date begin fertilizing with Fox Farm Grow Big liquid plant food by diluting ½ teaspoon per gallon of water. Put this dilution in a squeeze bottle and fertilize the plants once a week while they are in their seed starter cells.
Let the little plants grow for about 6-8 weeks until they have made 4 true leaves, for a total of 6 or more leaves on each plant. It's good to give them air circulation with a fan, and/or brush them daily with your hands. This helps the seedlings grow stockier stems and prevents them from getting leggy.
After 6-8 weeks of growing, it is time for them to visit the great outdoors. The following instructions are for southern California. At the end of March, it may get to about 70 degrees F during the day and about 50 degrees at night. Each day the tray is placed outside on a table under the patio cover. This patio cover is a slated roof, so they get partial sun all day. Then the tray is brought inside every night and placed on the floor. When the tray is outside the little plants are getting wind, temperature swings, sun, shade and sometimes rain. This is keeping the pepper plants short and not too tall as might happen with an artificial light bar. On very cold days, the tray stays inside in bright light.
After two weeks in partial sun, they are placed on a table at the west end of the patio for partial sun plus full sun for about 2 hours in the late afternoon. On milder nights, the tray stays outside. Now they are really growing fast with a lot more leaves and are about 3” tall. Keep them on the patio for about 6 weeks until they become root bound with a healthy root system.
***Check out Growing Carolina Reapers - Part 2 - In the meantime, prepare for transplanting the pepper plants from the small cell tray into 4” x 4” pots filled with Pro-Mix Premium Organic Vegetable and Herb Mix. If you do not have a growing bench for all 72 of the 4” x 4” pots, a modification will be included.