Ultimate Guide to Growing Jalapenos

Known for their medium hot punch, Jalapenos are a popular chili pepper. Interestingly, despite being classified as a perennial vegetable, these plants are usually grown as warm weather annuals. Members of the Capsicum annuum species along with sweet bell peppers, cayennes and habaneros, the jalapeno  shares many of the same growing likes and needs as other pepper plants.

An increasingly popular member of the vegetable garden, in the right conditions jalapenos are pleasingly easy to grow. Just remember to harvest the fruit before the color changes. If you want to spice up your vegetable garden, jalapenos are a great place to start. Here is your complete growing guide.

Jalapenos are an increasingly popular addition to the vegetable garden.

Different Varieties of Jalapenos

A number of different varieties of jalapenos have been developed over the years. Today you can get cultivars in a range of different sizes and heat levels. In addition to the typical red and green cultivars you can also find white and even purple plants. In terms of heat, some varieties register 30,000 SHU on the Scoville Heat Scale while others are a lot cooler. This means that regardless of your growing conditions and own personal tastes you are sure to find at least one suitable variety.

Some of the most popular and reliable jalapeno varieties are:

• Mucho Nacho is a quick maturing variety, taking about 68 days. The mild tasting peppers, 5,000 to 10,000 on the SHU scale, are about 4 inches long.
• Billy Biker is a prolific plant, reliably producing high yields. The peppers measure 5,000 to 10,000 SHU.
• TAM Jalapeno is a great choice if you want the flavor of a jalapeno without too much intense heat. The green or red fruit measure around 4 inches long and measure 1000 to 3500 in the SHU.
• Senorita is a hybrid plant, producing dark green fruit that first turns purple and then red. The 3 inch long peppers have a SCH rating of just 400. This makes it another great choice if you want a pepper without any of the heat. Taking 80 days to mature from seed, mature Senorita plants are about 2 ft in height.
• Sierra Fuego is a hybrid, producing mildly hot fruit, measuring 4000 to 6000 units, that is about 3 to 4 inches long. The fruit matures around 80 days after sowing.

Jalapenos come in a range of shapes, colors and different heat intensities. 

You can grow jalapenos from seed or purchase young plug plants, ready for transplanting into the garden from your local garden store.

When selecting a variety, try to select one that is suitable for your growing conditions. Some varieties require up to 4 months of growth until the fruit is ready to harvest. In colder climates growers may have more success purchasing young plants from the garden center or nursery than growing from seed. This enables you to make the most of the shorter growing season.

Growing from Seed

Start your jalapenos in the spring, for an early start you can start the seeds undercover. Try to give yourself as much growing time as possible. This means sowing around 10 weeks before you aim to plant out the seedlings.

To sow the seeds, fill a seed tray with fresh potting soil, Moisten the soil. Sow the seeds as thinly as possible, roughly half an inch deep. Cover the seeds with a light layer of soil.

Most varieties require warm soil temperatures of 65 to 80 ℉ and at least 16 hours of light every day to germinate successfully. If you struggle to replicate these conditions grow lights and a heat mat can help.

Grow lights and heat mats can help to maintain ideal germination conditions. 

Following germination, keep the seedlings covered until they are at least 2 inches tall. When the seedlings reach this height gradually remove the protective cover, introducing more circulating air and lowering humidity levels.

Once the seedlings have been acclimatized move the tray to a sunny windowsill. Continue to water or mist the soil, keeping it evenly moist.

When the seedlings are 6 to 8 inches tall, harden them off before transplanting outside.

Where to Plant Your Jalapenos

Jalapenos, like other peppers, are full sun loving plants. Particularly in warmer climates, a position with a little afternoon shade is fine. Be careful not to plant in too shady a position. This can cause plants to become leggy and may deter fruit production.

While they are not the most delicate plant in the vegetable garden, young plants in particular benefit from some protection from frosts. You should also shelter them from high winds.

The soil should be fertile and well draining. A loamy soil is ideal. Before planting, dig over and weed the soil. You can also use this opportunity to work in lots of organic matter to improve the soil. A pH level of 6.0 to 6.8 is ideal but the plants can tolerate conditions slightly outside this. If you are unsure of the makeup of your soil, use a soil test kit to determine if any improvements are necessary.

Prepare the soil before planting. 

How to Plant Your Jalapenos

If it isn’t warm enough your transplants will fail. Allow the soil to warm up before transplanting. A Stainless Steel Soil Thermometer provides an accurate way to monitor the temperature of your soil. In general, most growers like to wait until about 2 weeks after planting out tomatoes to plant out their pepper plants.

To transplant, make a hole in the soil large enough to hold the seedling’s root system. Carefully remove the seedling from the tray, being careful not to damage the root system. If the roots are compacted together, gently tease them apart.

Position the seedling in the center of the hole and backfill. Be careful not to sink the seedling as you fill the hole. When planted the seedling should sit at roughly the same level in the ground as when it was in the tray.

After planting, water well. Space your jalapenos 14 to 16 inches apart. The larger the specimen the more space it requires. Rows of plants should be spaced 2 to 3 ft apart.

Roughly 3 weeks after planting, when transplants are established, mulch the soil heavily. This helps to conserve moisture. An organic mulch also slowly breaks down, providing the plants with a nutrient boost.

Growing in Pots

You can also grow jalapenos in pots or planters. Most varieties of jalapeno are considered medium sized plants. This means that they should be planted in a 4 to 5 gallon pot. While the plants can happily grow in smaller containers, fruit production may not be as heavy.

Fill the pots with a balanced potting mix and plant as described above.

Caring for Jalapenos

Once planted and established, jalapenos are pleasingly easy to care for as long as the temperature remains warm. Regular exposure to temperatures below 65 ℉ may cause blossom drop. As can temperatures over 90 ℉. Growers in unpredictable climates may have more success growing their jalapenos in a greenhouse or cold frame.

Jalapenos prefer humidity levels to average between 50 and 70 %. Again, growing in a greenhouse or using a humidifier can help to maintain ideal humidity levels. If you are growing the plants outside, regularly water to prevent the soil from drying out. Regularly watering helps to maintain humidity levels around the plants.

When to Water

Growing pepper plants like lots of water. If it doesn’t rain, water the plants deeply every 2 or 3 days. Regularly watering the plants during warm and dry spells helps to prevent fruit drop.

While jalapenos like lots of water, these plants shouldn’t be allowed to sit in soggy soil. Your soil should drain excess water away. If your soil is too well draining, a thick layer of mulch helps the soil to conserve moisture.

When watering the plants, try to keep the fruit as dry as possible. Drip irrigation or a watering can should be used, either method gives you more control when watering, helping to keep plants dry and soil properly watered. The best time to water your plants is in the morning. This means that if you do get the foliage wet it has lots of time to dry out in the sunshine before the cooler evening temperatures arrive.

Don’t allow the soil to dry out. This can cause leaf drop. 

Fertilizing Growing Plants

Just after transplanting your seedlings, apply a slow release fertilizer. This gives them a nitrogen boost and helps the plants to settle in their new position. Around 3 weeks later follow this up with a small dose of balanced fertilizer. This nutrient boost helps to promote healthy growth.

Fertilize growing jalapenos regularly during the summer to encourage fruit production. Apply a 5-10-10 or equivalent fertilizer as soon as flowers form. Regularly repeat this application during the growing season as prescribed by the information on the fertilizer label. If you are growing jalapenos in poor soil or containers apply balanced granular fertilizer around the base as soon as fruit begins to form.

As the growing season draws to a close, begin to gradually reduce the amount and regularity with which you fertilize.  

Pruning Your Plants

You can begin pruning plants as soon as they are 6 weeks old. When pruning remember that you are aiming to keep the plant lower and sturdier. Correctly pruning plants can help to promote flowering and improve yields.

When pruning your plants, try to remove any suckers or stems that are too thin. This encourages the plant to focus its energy into the healthier stems, boosting flower and fruit production. You should also cut away disease or damaged leaves and stems. Finally, don’t allow the growth to become too dense. This can hamper air circulation leading to mold and fungal issues.

Allow the peppers plenty of room to form and develop.

Companion Plants

Basil helps to improve the flavor of jalapenos and other pepper plants. Chamomile and marigolds drive away nematodes and eelworms, helping to keep plants healthy. Herbs such as chives, dill, coriander, parsley and garlic also make good companion plants.

Jalapenos also do well alongside a number of  vegetable plants, in particular:

• Asparagus.
• Carrots.
• Cucumbers.
• Eggplants.
• Peppers.

Finally, nasturtiums are good companion plants because they attract masses of pollinators to the garden.

Avoid planting near beans and peas. Members of the brassica family, such as cabbage and broccoli, should also be avoided.

Propagating Jalapenos

Collecting and sowing seeds is a pleasingly easy way to grow productive jalapenos year after year. But be careful, hybrid varieties won’t grow true to type. If you are growing outside, or amongst a range of different pepper plants, they may also cross pollinate during the growing season. This means that the seeds won’t produce true replicas of your plants and are often disappointing.

To harvest the seeds simply remove them from mature fruit. Dry the seeds on a windowsill before storing in a paper envelope until you are ready to start sowing.

Propagating from Cuttings

While growing from seed is easy you can also propagate from cuttings. This method guarantees that the new plants are true replicas of the parent plants.

Always take cuttings from healthy stems or branches. Make a clean incision about 6 to 8 inches from the tip of the plant. Dip the cut end in water and then a rooting hormone.

Plant the cutting in a pot filled with moist potting mix. Cut away all but the top leaves from the cutting before placing it in a propagator or plastic cover. Place the propagator in a light position. Don’t allow the soil to dry out, regularly water or mist. New growth and roots should soon form.

Common Jalapeno Problems

Jalapenos, and other pepper plants are prone to many of the same issues as other members of the nightshade family such as eggplants and tomatoes.

Fusarium wilt is a nasty fungal disease which causes plants to weaken and foliage to yellow. You can prevent fusarium wilt by correctly spacing out your plants, to improve air flow, and keeping the foliage as dry as possible when watering. Once plants develop fusarium wilt, there is no cure. Dig up and destroy affected plants.

Planting and correctly caring for the plant helps to keep it healthy and productive. 

Cucumber mosaic virus is another nasty disease with no cure. Causing mottled coloring on foliage and stunted growth, fruit from affected plants is still edible but won’t be as good as fruit from healthy plants.

Anthracnose is a common fungal disease which creates dark, sunken spots on the fruit. Dig up and destroy affected plants. If this is a particular problem, you can now purchase anthracnose resistant varieties.

Foliage rolling downward can be caused by changes in temperature or weather conditions.

Plants producing lots of healthy green foliage but no fruit should be treated with a phosphorus rich fertilizer or similar amendments.

Aphids can target the foliage. Applying insecticidal soaps, which can be made at home, or introducing ladybugs and predatory insects can help to curb infestations.

The larva of the cucumber beetle can target root systems. They can also make holes in the foliage. To deter cucumber beetles, regularly weed the soil around the plants, keeping it as neat and tidy as possible. Should the pests make it to your plants, use sticky traps to catch them before they do too much damage.

Pepper hornworms are green caterpillars that create large holes. These can simply be picked off the foliage.

Finally, mites may also strike, causing foliage to fade and distort. These pests are almost impossible to see and even harder to counteract. Dig up and destroy affected plants.

Harvesting Jalapenos

As they ripen, jalapenos change from a light green color to a darker green and then a red. Some cultivars may change to other colors. For maximum flavor harvest the fruit when they are at least 4 inches long or when the fruit is a rich, dark green. Allowing fruit to fully ripen and redden produces sweeter fruit that isn’t as hot.

To harvest your fruit, simply cut the stem about half an inch above the fruit.

 Store fresh peppers in a paper bag in the refrigerator crisper dray. Here the peppers can keep for up to a week.

For long term storage dry the peppers by threading a sewing needle. Sew through the end of the stem where it meets the pepper. Hang up to dry in a cool, dark place with good airflow. Once dry they can be smoked, to turn into chipotles, or ground up into a powder. You can also freeze jalapenos either chopped up or as whole peppers. This is best done if you intend on cooking them at a later date. Freezing softens the fruit meaning that they lose their crispness.

If your peppers are too hot, try removing the seeds. This helps to cool them down.

As the growing season comes to an end and temperatures begin to fall, fruit production will slow. Jalapenos are heat sensitive plants, meaning that they won’t survive a frost. When temperatures threaten to drop below 35 ℉ harvest all the fruit and dig up the plants. Old plants can be placed on a compost heap. Unripe fruit can be ripened indoors on a bright windowsill.

Spicy and easy to grow, these peppers are an increasingly popular addition to the garden. 

Spicy and delicious, jalapenos are a staple of mexican cuisine. Happy to be roasted, baked or grilled with a little work they will happily thrive in your vegetable garden.