Jalapeño Pepper Plant Profile

Jalapeno Pepper Plant

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The jalapeño pepper is a chili-type cultivar of the Capsicum annuum species, a species which also includes sweet bell peppers, habanero peppers, and cayenne peppers. Jalapeño falls in the middle of the pack in terms of spiciness, with a medium-hot punch. These peppers have the same cultural needs as other cultivars of the species, but they are typically harvested just before the pod-shaped fruits turn color.

Jalapeño peppers are planted in spring from nursery starts or from seeds started indoors. Peppers need warm temperatures to germinate, so they should be planted after soil temperatures reach at least 65 degrees Fahrenheit. It takes three to four months from germination for jalapeños to produce fruit that can be harvested.

Botanical Name Capiscum annuum 'Jalapeño'
Common Name Jalapeño pepper, jalapeño
Plant Type Perennial vegetable, usually grown as an annual
Size Up to 3 ft.
Sun Exposure Full sun
Soil Type Fertile, moist, well-drained
Soil pH Acidic to neutral (5.8 to 6.8)
Hardiness Zones 11 (USDA); grown as an annual everywhere
Native Area Tropical regions of Central and South America
Toxicity Could be mildly toxic in large doses 

How to Plant Jalapeño Peppers

Jalapeño peppers are often planted from nursery seedlings, especially in colder climates where the growing season is short. Space the plants about 14 to 16 inches apart, with about 2 to 3 feet between rows.

If planting from seeds, peppers will need to be started indoors in trays, at least 10 weeks before outdoor planting time. Expose them to at least 16 hours or artificial light during the germination period, then move them to a sunny window once they have sprouted. Seedlings will need to be 6 to 8 inches tall to ensure successful outdoor planting; they may already be in flower.

After about three weeks in the ground, mulch heavily around the plants to help conserve soil moisture and provide nutrients.

Jalapeño Pepper Care

Light

Plant jalapeño peppers in a full sun location. While they will tolerate a bit of shade, the plants will be spindly and the fruit production less than ideal.

Soil

The ideal soil for peppers is fertile, moist, and well-drained. If the soil is less than ideal, mix in plenty of organic matter before planting. Peppers do not do well in dense, soggy soil.

If growing peppers in containers, any general-purpose potting mix will be sufficient.

Water

Unlike some other members of the nightshade family of plants, peppers need lots of water. Water them deeply every two or three days, but don't allow the roots to soak in water constantly—a well-draining soil is crucial. A thick layer of mulch will help conserve soil moisture.

Temperature and Humidity

Peppers grow best in a fairly narrow range of warm temperatures. Temps below 65 degrees Fahrenheit may cause blossoms to drop, and the same thing happens when temperatures regularly exceed 90 degrees.

Fertilizer

Feeding is usually not necessary if the soil is rich, but peppers growing in poor soil or in containers will benefit from an application of a balanced granular fertilizer around the base of each plant immediately after the fruit begins to form.

Is Jalapeño Pepper Toxic?

The "heat" in hot peppers comes alkaloid chemicals called capsaicinoids found in the plant. Technically, these are toxins, and in some peppers, they can cause severe skin irritation and throat swelling. Jalapeños, however, contain relatively small amounts of the chemical and thus there is little danger. However, dogs or unsuspecting humans who eat too many jalapeños may experience mild gastrointestinal symptoms.

Jalapeño Pepper Varieties

Over time, breeders have introduced a number of varieties of the popular jalapeño pepper. All peppers belong to the species Capsicum annum, so the differences attributed to each pepper are mainly regarding appearance and heat. Jalapeño peppers vary in size, color, and the amount of heat they provide. There are white and purple jalapeno varieties, in addition to the common green and red varieties. On the Scoville scale of pepper hotness, they range up to about 30,000 Scoville heat units (SHU( for very hot varieties, while a habanero pepper can get as high as 800,000 Scoville units. Some popular varieties include:

  • 'Seniorita' ripens to a dark green that turns purple, then red. The peppers are about 3 inches long, with a Scoville rating of 5,000. It takes 80 days to mature from seed to harvest; plants grow about 2 feet tall.
  • 'Fresno Chile' produces smaller, 2-inch peppers with a heat rating of only 300 to 400 SHU.
  • 'Sierra Fuego' is a hybrid variety that produces mildly hot 3 1/2-inch peppers. It matures in about 80 days.
  • 'Mucho Nacho' matures quickly, in about 68 days. The peppers are 4 inches long and relatively mild in taste.

Harvesting

As they ripen, jalapeño peppers transform from light green to glossy dark-green and then to red. For a maximum spicy flavor, they should be harvested when they are full size (usually about 4 inches or more), at the point where they turn dark green but before they begin to turn red. If left on the plant to fully ripen, the peppers will be sweeter and less hot, though still tasty.

Peppers will not survive even a hint of frost, so if temperatures below 35 degrees Fahrenheit are predicted, you should harvest all remaining peppers and continue to ripen them indoors by placing them in a bright window.

Common Pests and Diseases

Like all vegetables, peppers are susceptible to a variety of insect pests and disease issues, many of them common to other members of the nightshade family, such as tomato and eggplant.

  • Aphids are one of the most common pests. These tiny green or white insects suck the sap from the leaves, reducing the vigor of the plant and making it more susceptible to diseases. If possible, use a non-toxic control method, such as predatory insects like ladybugs, or insecticidal soaps or oils. If chemical pesticides are unavoidable, use one that breaks down quickly, such as one containing pyrethrins. Be aware, though, that all chemical pesticides have the potential for killing beneficial insects.
  • Cucumber beetle larvae may damage the roots of young plants. These small yellow-green beetles with black stripes eat small holes in the leaves. Keeping the area free of weeds will help eliminate the beetle breeding areas.
  • Pepper hornworms are greenish caterpillars that chew large holes in the leaves. The best remedy is to pick off the worms by hand.
  • Mites are nearly invisible insects that cause distortion or discoloration of the leaves. Affected plants should be removed and destroyed.
  • Fusarium wilt is a fungal disease that causes plants to weaken and turn yellow. Affected plants will need to be removed and destroyed. Keeping plants healthy and well-watered usually prevents this disease.
  • Anthracnose is another common fungal disease, creating dark sunken spots on the fruit. Remove and destroy affected plants, and make sure to buy resistant varieties when you next plant.

How to Grow Jalapeño Peppers in Pots

Jalapeño peppers can easily be grown in pots filled with ordinary potting mix, but be prepared to water and feed them more frequently than you would with in-ground plants. Growing in containers does allow you to move the plants around to give them the copious amount of sunlight they need. And peppers are perennial plants, which means that you can grow them year-round indoors, provided you can give them the sunlight they need.

Ideally, potted peppers should have a 3-gallon container, but they will survive in a somewhat stunted fashion if grown in a 1-gallon container.