How To Grow And Care For Jalapeños

Peppers are an amazingly diverse group, with varieties ranging from unbearably spicy to sweet and mild. Jalapeño peppers (Capsicum annuum) are related to cayenne, poblano, and bell peppers, and are the most popular variety among gardeners looking for a bit of heat. They are a featured ingredient in a variety of cuisines from around the world. Jalapeños are also very easy to grow in the vegetable garden or patio containers. You can even tuck the plants into a flower bed.

The spiciness of a jalapeño comes from a compound called capsaicin, which is produced in the seeds and the cream-colored membrane found inside the fruits. If you want to maintain the heat when cooking, do not remove the seeds or membrane. Jalapeños are considered mildly hot, ranging from 2,000 to 8,000 on the Scoville scale. They are spicier than poblanos, but not as hot as serrano peppers.

People aren’t the only ones to like the heat. Pepper plants thrive in warm climates and do not tolerate frost. As such, they are planted in late spring once it's warmed up. Jalapeños are usually grown as an annual, quickly maturing in two to three months and producing peppers until frost arrives in fall. In cooler regions with short growing seasons, look for fast-maturing cultivars, often containing “early” in their name, to ensure a harvest. Here's everything else to know about growing jalapeños in the garden.

Plant Attributes

Jalapeño Care

Jalapeño peppers make an easy crop for new and experienced gardeners alike whether you are growing them in a pot on your balcony or in the ground. When it comes to producing peppers, location matters. Find a sunny spot that receives at least six to eight hours of full sun each day. Also, look for a sheltered location as peppers do not tolerate heavy wind.

As a tropical plant, jalapeños are planted as seedlings called transplants in spring well after the threat of frost has passed. Look for transplants with sturdy stems and six to nine leaves. Inspect plants for signs of damage or disease. Avoid transplants that already have flowers or fruit, as this can be a sign of stress. Even and consistent watering is key to maintaining a healthy pepper plant and producing high-quality fruits, which will last until the first frost in fall.

Light

Peppers are full-sun plants that need six to eight hours of direct sunlight a day. That being said, if you live in a very dry or blazing hot climate in the Coastal South, it's a good idea to use a shade cloth or provide some protection from the afternoon sun during the heat of summer. The plants may dry out too quickly otherwise.

Soil

Peppers perform best in a well-draining, loamy soil high in organic matter. They also tolerate sandy soils and those with moderate fertility, but will produce more fruit if you mix compost into the soil at the time of planting. Clay soils should be amended with organic matter to improve drainage. Peppers can tolerate neutral or slightly alkaline soil, but do best in slightly acidic soil.

Water

This tropical fruiting plant looks its best when provided with even moisture, but excessive rainfall and soggy soil can lead to disease. Between watering and rainfall, peppers need 1 to 2 inches of water a week. Irrigate plants in the morning to allow water to dry from foliage during the day as this reduces the chance of disease. Using drip irrigation is another great option. Water plants deeply when watering to prevent shallow root growth.

Consistent moisture is especially important while the plants are blossoming and setting fruit. Peppers require more frequent watering during hot weather. Wilting leaves are a sign to give your plants a good drink. A layer of mulch helps to preserve soil moisture, but wait until soils have warmed to apply mulch. Watering and irrigation encourage weed growth. Carefully weed around plants to reduce competition, taking care not to disturb roots.

Some gardeners believe that peppers get spicier during the stress of hot, dry weather, and will reduce watering slightly once fruit appears. However, this phenomenon isn't consistent and may depend on the variety you are growing and a combination of environmental factors.

Temperature And Humidity

Wait to plant peppers until two weeks after your last frost, as jalapeño plants are sensitive to cold soil and air temperatures. Transplants won't start actively growing until the soil temperature reaches 65° F. To prevent damage, cover plants on cold nights that dip to 40° F or below at the beginning of the season. Blossoms can drop when nighttime temperatures are below 60° F. Though these plants like the heat, they also may drop blossoms and temporarily stop producing fruit once temperatures climb above 90° F. Pepper plants thrive in humidity and need more frequent watering in a dry climate.

Fertilizer

Mixing compost into the soil at planting time will give your peppers a good start. If you want to maximize your harvest, you can apply a slow-release, organic granular fertilizer for tomatoes or vegetables. Apply every four to six weeks or according to package directions. Avoid over fertilizing, as this can damage plants.

Types Of Jalapeño Peppers

• 'Mammoth': This whopper of a plant produces 4 or 5-inch peppers and can grow to 2 to 4 feet tall. The thick skin makes these medium-spice peppers easier to stuff.
• 'Coolapeño': This "heatless" variety has the delicious flavor of jalapeños for those with more sensitive palates. The peppers turn sweeter if you allow them to ripen to red.
• 'Early': Rounder, 3-inch peppers appear a few days earlier than most plants. 'Early' is a compact 18 inches, making it a good patio plant. They are in the middle of the range of spiciness.
• 'Jaloro': This introduction from Texas A&M is also compact and has small, sweet, mildly spicy fruits. The peppers go through a colorful transformation from pale yellow-green to orange to red.
  
• 'Super Nacho': Supersized peppers can be 6 or 7 inches long, providing plenty of slices for your nachos. 'Super Nacho' is as spicy as jalapeños come.

Pruning

While not required, pruning pepper plants allows them to develop stronger, bushier growth. When plants are about 12 inches tall, cut or pinch the stem back to the second or third set of leaves. This is called topping or tip pruning. The plants respond by sending out branches along the stem, resulting in a fuller, stronger plant.

It's a good idea to prune peppers three or four weeks before the first fall frost to encourage fruits to finish maturing. Remove branches that don't already bear fruit and prune the rest back by 6 inches or just above the topmost fruit.

Jalapeños are typically harvested in the immature, green stage. Like other peppers, jalapeños start out green and change colors as they ripen, in this case, turning bright red. Mature, red jalapeños are certainly edible and tend to become hotter the longer they remain on the plant. Use pruners to remove clip off peppers without damaging the plant.

How To Grow Jalapeños From Seed

You can easily start jalapeño from seed indoors, starting them about eight weeks before the expected planting date following these steps:

1. Fill a seed-starting tray with seed-starting mix and moisten.
2. Sow seeds 1/4-inch deep. Keep moist and maintain soil temperature of 75-85° F for good germination. A heat mat can be helpful for providing warmth.
3. Seedlings should sprout in 10-21 days. Place seedlings under a grow light or in a bright, sunny window.
4. Once seedlings reach 3 inches tall, transplant them into individual containers such as a 3-inch or 4-inch pot. Use fresh potting mix and fertilize with indoor houseplant liquid fertilizer at half strength.
5. Begin to harden off plants two weeks after your last frost. Gradually expose them to sunlight, starting in a sheltered location. Bring them indoors at night if temperatures get too cold. After a week of gradually increasing sun exposure, plant peppers outdoors in prepared soil at least 18 inches apart.
   

Potting And Repotting Jalapeños

If you are growing in containers, select a large pot (12-14 inches wide or at least 5 gallons) with a drainage hole to allow the roots room to spread out. Use a potting mix with plenty of organic matter such as composted pine bark, coir, or rice hulls to prevent compaction and provide good drainage. Peppers are usually spaced 18 inches apart in the garden, but you can group two or three more compact types together in a larger planter such as a half barrel.

Containers will need more frequent watering than in-ground plants. Allow the soil to dry out slightly between waterings. If you notice roots growing out the bottom of the pot and it becomes difficult to keep your plants hydrated, select a slightly larger container and repot plants in fresh potting mix.

Overwintering

Because the jalapeño plant is a tender tropical perennial, you can overwinter it indoors. Most gardeners simply start over from scratch the next season, but there are a couple of good reasons to overwinter your pepper plant if you'd like to take on this project. One, the plants will develop much faster once you move them back outside. Two, a more mature pepper plant will have a higher yield.

Unless you have a temperature-controlled greenhouse or a grow-light system indoors, you'll be overwintering the plant in dormancy. Wait until the plant begins to drop its leaves in the fall, but not so late that it is killed by a frost. This is usually when nighttime temperatures dip into the mid-40s. Repot the plant in a clean container and fresh potting mix to reduce the possibility of disease. Remove leaves and prune branches back so you keep a few of the main Ys, cutting just above a node on each branch. Place the container in a cool, sheltered area with a little bit of ambient light, such as a garage, that stays around 55-60° F. Water the container every three to four weeks. Harden off the plants gradually outdoors once it's warm enough to transplant.

Common Pests & Plant Diseases

Peppers are fairly disease-resistant, but are susceptible to a number of diseases in wet weather. Good air circulation and soil drainage, as well as avoiding overhead watering, can go a long way to preserving the health of your plants. Plants that develop phytophthora blight (plants girdle at soil line and wilt), verticillium wilt (leaves cup, yellow, wilt, and drop), or mosaic virus (stunted growth, streaked and spotted leaves, curling leaves) should be discarded. Avoid planting peppers in the same area for three or four years. Plants with significant damage from leaf spots should also be discarded. Remove diseased foliage from remaining plants. Spray plants with a copper fungicide or consult with your local extension office.

Insects may also transmit disease between plants. Keep the surrounding area weeded and use insecticidal soap if aphids, flea beetles, leaf hoppers, or spider mites become a problem. Spider mites can be controlled by knocking them off with a strong spray of water every couple of days. Cutworms will decapitate plants at the base; if you can catch them in time, control by spraying Bt.

Common Problems With Jalapeños

Pepper plants tend to be fairly trouble-free. Proper watering and soil fertility can help combat some of the most common problems with growing peppers described below.

Sunken Spots On Fruit

Blossom end rot is a disorder caused by environmental factors, not a disease agent. Blossom end rot begins as a light green or yellow colored sunken area at the base of the fruit, which expands to a larger collapsed area that takes on a black color. 

Blossom end rot is linked to calcium deficiency resulting from irregular water supply to the plant. Most soils contain sufficient calcium, so supplemental fertilization is not usually the solution. Rather, maintaining an even moisture supply to the plants will allow plants to take up calcium as needed and reduce the incidence of blossom end rot. 

Scalded Fruit

Sunscald is also a physiological disorder, not a disease. It occurs when pepper fruits are exposed to direct sunlight during hot weather. Symptoms appear only on the side of the fruit facing the sun and include white or yellow blistering of the fruit, which becomes papery, flattened, and grayish with continued exposure. Minimize sunscald by encouraging dense foliage through proper water and fertilization. Some cultivars are more susceptible to sunscald than others, so look for resistance when selecting varieties to grow in the garden.

Yellow Leaves

Disease isn't always the culprit when pepper leaves turn yellow. Poor soil fertility and over watering are both possibilities. Wait to water until the top inch or two of soil is dry. Apply fertilizer if you haven't done so yet, or have your soil tested at the local extension office to see if you're missing key nutrients such as nitrogen, phosphorus, or calcium.