Hot Stuff: A Gardener’s Guide to Jalapeño Peppers
Whether you’re chasing heat or just love the crunch, jalapeños are a garden favorite with a fiery personality. Like all peppers, sweet and hot, jalapeño peppers belong to the species Capsicum annuum, in the family Solanaceae (the nightshade family). Originating in Mexico and Central America, peppers were domesticated as early as 7500 BCE. Hot peppers can contain varying amounts of capsaicin. Jalapeño peppers usually range from 2500-5000 Scoville units. If you want to reduce the heat, you can remove the seeds and inner membrane where the capsaicin is more concentrated. Since peppers are tender perennials, they are grown as annuals in colder climates.
Starting Hot Peppers from Seed
Since peppers require a long, warm growing season, they need to be started indoors. Transplant them outside after danger of frost has passed and the soil has warmed up. Six to eight weeks before the average last frost in your area (typically mid-April to early May in many regions), plant the seeds 1/4-inch deep in sterile potting mix. Keep the soil moist, but not wet, and don’t forget to label your trays with the cultivar and record the planting date. Germination should occur in about 10 days. Peppers grow best when the soil is between 80-90°F. A seed mat placed under the trays can help maintain this temperature.
Transplanting
About a week and a half before transplanting to your garden, start to harden off your jalapeños. Start by placing them in a shady, protected area outside for an hour or two. Gradually let them spend more time in the sun every day until they spend the entire day in full sun. Peppers do not like cool temperatures, so be sure to bring them inside if the temperature dips below 40-45°F. Personally, I prefer to bring them in if the temperature is below 55°F, especially early in the season when they are still adjusting. Wind can be just as stressful as cold to a young pepper plant. Be sure to place the seedlings in an area protected from strong winds. Once your peppers are basking in full sun and the soil is warm, it’s time to get them settled into their summer home.
Choose a place with at least 6-8 hours of direct sunlight. Partial shade will cause them to grow slower and take longer to produce fruit. Work the soil in your garden 7 to 8 inches deep, so your peppers have plenty of room to grow a strong root system. Dig a hole slightly larger than the container your seedling is in. At this point I like to add a fertilizer like Tomato-tone to the hole before I set in the plant. Gently remove the seedling from its container and massage the root ball to loosen up the roots and allow them to spread out. Place your pepper plant in the hole and tuck soil around the roots, keeping the stem at the same level above the soil as it was in the pot. Your plants should be spaced 12-18 inches apart in a double row, leaving about 2 1/2 to 3 feet between rows. Now that your jalapeños are in the ground, water them well to reduce transplant shock.
Growing & Fertilizing
Peppers love warmth, growing best at temperatures 70-80°F during the day, and 65-75°F at night. Fruit set occurs best when the temperatures between 75°F and 86°F, when the nighttime temperatures dip below 72°F, fruit set will be poor. When temperatures are above 90°F or below 55°F, heavy blossom drop will occur. Unfortunately, the flowers are lost before they even have a chance to set fruit.
Keep the soil evenly moist, especially during flowering and fruiting. Deep watering once or twice a week is better than frequent shallow watering. Avoid letting the soil dry out completely, but don’t drown them either, peppers dislike soggy feet. Ideally they should be getting 1 inch of water a week, including rain. Mulching around the base of the plant will help retain moisture and suppress weeds.
Peppers usually do not need a lot of support. Occasionally a plant will need a little extra help from a stake tied gently to it. Use twine, yarn, or even strips of fabric, never wire or anything that will rub or potentially cut into the stem.
I fertilize every two weeks until the nighttime temperatures dip below 55°F. I continue using Tomato-tone throughout the season, adding about 2 tablespoons around the base of the plant and working it into the soil, being careful to avoid disturbing the roots. I water well after each fertilization.
Harvesting
Jalapenos are typically ready to harvest 70 to 85 days after transplanting. This depends on the variety and growing conditions. More precise information can be found on the seed packet (if you have grown them from seed), or possibly on the tag that came with the seedling (if you bought your plant from another grower).
Once the peppers are 2-4 inches long and firm and glossy, they are ready to harvest. You can harvest when they are a dark green or leave them on the plant to turn red for a more complex, slightly sweeter flavor. Try some both ways and see which you prefer. I usually harvest some while they are green and get some while they are red to add flavor and visual appeal to whatever dish I am preparing.
While using garden shears or scissors is the suggested way to harvest, I usually harvest peppers by giving them a gentle tug. While it is possible to damage the plant or end up pulling off branches this way, I prefer this method. It lets the peppers tell me when they are ready for harvest. If they don’t release with a gentle tug, I will leave them to grow for a few more days and try again.
Pepper plants will continue to set fruit, so harvest often to maximize your pepper production. That being said, hot peppers produce a stronger flavor if left on the plant to ripen. After harvesting, you can wrap them in a clean damp cloth to maintain high humidity. Store them in a cool, but not cold place, preferably 45-50°F. This will help them keep for about 2 weeks.
Whether you’re growing jalapeños for salsa, pickling, or just the thrill of the heat, these peppers reward patience with bold flavor and garden beauty.