Different varieties of peppers take different amounts of time to grow, with hot peppers taking the longest, about 12 weeks until maturity, and bell peppers taking about 8 weeks to reach maturity. Find out when your 100% certain last frost date is in your grow zone and count backwards 8-12 weeks to decide when you will need to start your seeds. Peppers will not thrive in cool soil, so planting outside early offers no advantage.
Peppers are slow to germinate and get going, and will rarely sprout without supplemental heat, so a heat mat or other source of warmth will be needed to start your seeds.
Soaking your pepper seeds is helpful to help break down the hard seed coats, and in fact we’ve had great luck soaking the seeds for 2-6 hours in a weak, room temperature, chamomile tea. The Chamomile helps disinfect the seeds and break open the seed coat, helping speed up germination.
Sow seeds in your favorite sterile seed starting mix. Plant seeds about 1/8” below the surface of the soil and mist well. You’ll need to keep the soil moist but not wet until germination, a humidity dome will help a lot with this. When your seeds have sprouted, remove your humidity dome and keep the soil watered as often as needed to keep the soil moist but not wet while your babies grow up.
Peppers are heat and sunshine lovers, and supplemental lighting will be needed to grow healthy and happy plants. Even the sunniest of windows are not going to provide enough light to grow this summertime crop.
When your pepper plants have their first true leaves, give them a gentle feeding of a weak compost tea. Repeat this feeding a few days before you start to harden off your seedlings for planting outside. Pepper plants are delicate and need to be gradually exposed to a colder outdoor environment before they are transplanted entirely. This process is called ‘hardening off’ and should be started when your plants are between 4-6” tall, at least a week before you will be planting outside. Start by placing your seedlings outdoors for a few hours each day, in an area protected from direct sunlight and wind. Slowly extend the number of hours the plants stay outside as they continue to grow. Avoid leaving the peppers outside overnight until you’re almost done hardening them off.
Prepare your garden beds for planting by working in an inch or two of good compost, and having some stakes ready to pound in next to your plants for support. Especially bell peppers can become quite heavy when loaded with fruits.
When your seedlings are completely hardened off, plant your seedlings about 18” apart. Mulch your plant with straw or grass clippings. Water in well, and water regularly throughout the growing season. While peppers can tolerate some drought, they are susceptible to drought related stress that can seriously affect production or make them vulnerable to bug or disease pressure.
Slow growth or the appearance of pale leaves are indicators that your pepper plants need fertilizing. Choose a high nitrogen fertilizer such as fish emulsion or compost tea and spread an even coating over the planting area. Follow the directions on your fertilizer bottle, and water before you fertilize so you don’t get run-off fertilizer.
Usually, peppers take around two months to mature enough to be harvested. To encourage your pepper plant to keep producing early in the season, harvest your peppers just before peak ripeness. Later on in the season when your plant is nearing the end of the production season, however, you can allow them to mature a bit longer before harvesting. The richer the color, the riper the fruit. Cut the pepper at the top of the stem. Pulling on your peppers can damage the fragile stalks and roots.