Banana Peppers in Zone 6A — Mountain West

Banana peppers are a fantastic addition to any Mountain West garden. Their mild, sweet flavor is delicious fresh, pickled, or grilled, and their versatility makes them a rewarding crop. Plus, the satisfaction of harvesting a colorful bounty in our short growing season is hard to beat.

Growing peppers at high altitude comes with challenges: intense sun, cool nights, and a relatively short 153-day growing season. But with careful timing and a few tricks, you can definitely enjoy a successful banana pepper harvest before the first frost.

Starting your banana pepper seeds indoors is essential in our climate. You'll want to sow your seeds mid-March through early April, about 8 weeks before you plan to transplant them outside. This gives them a head start and maximizes your chances of a good harvest.

Use seed trays or small pots filled with a good seed-starting mix. Keep the soil consistently moist but not soggy. Bottom watering is a great technique to avoid damping off. Provide warmth (a heat mat helps) and plenty of light – a grow light is ideal, as our spring sunlight can still be unpredictable. Remember our springs here can be late, so don't rush them outside.

Transplant your banana pepper seedlings outdoors mid-May through mid-June, once the danger of frost has passed. Before planting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the intense sun and cooler nights.

Choose a sunny spot with well-drained soil, spacing plants 18-24 inches apart. Even in late May, watch out for unexpected cold snaps or even hail, and be ready to cover your young plants if necessary.

Banana peppers need consistent moisture, but they don't like to be waterlogged. In our dry Mountain West climate, a good rule of thumb is to water deeply once or twice a week, providing about 1-2 inches of water each time, depending on rainfall.

Check the soil moisture by sticking your finger about 2 inches deep. If it feels dry, it's time to water. Focus on watering at the base of the plant to avoid wetting the foliage, which can lead to fungal problems in more humid climates (but not as much of a concern here!).

Signs of underwatering include wilting leaves and stunted growth. Overwatering can cause yellowing leaves and root rot. A layer of mulch, like straw or wood chips, can help retain moisture in our dry air and regulate soil temperature.

While banana peppers are bush-type plants, they can get quite prolific with long, heavy fruits. Providing some support is a good idea to prevent branches from breaking, especially after a heavy rain or hail storm.

Simple stakes or tomato cages work well. Install them at planting time to avoid disturbing the roots later. Gently tie the main stems to the support as the plant grows.

Pinching off the first few flowers that appear on your banana pepper plants can encourage them to focus on vegetative growth early in the season, leading to a stronger, more productive plant later on.

Otherwise, banana peppers don't require much pruning. Regular harvesting is the best way to keep the plants producing. As the first frost approaches in early October, remove any remaining small peppers, as they are unlikely to ripen in time.

You can expect your first harvest of banana peppers late July through mid-September, about 70 days after transplanting. Look for peppers that are pale yellow-green and 6-8 inches long. You can harvest them at any stage, from yellow to red, depending on your preference.

Gently twist or cut the peppers from the plant, being careful not to damage the branches. Regular harvesting encourages the plant to produce more peppers.

If a frost threatens before all your peppers are ripe, harvest them and bring them indoors to ripen. They will continue to ripen on a sunny windowsill.

Here are some common problems you might encounter with banana peppers in the Mountain West:

Blossom Drop

• What it looks like: Flowers fall off without setting fruit, or small fruit yellows and drops. The plant looks healthy otherwise.
• What causes it: Temperature stress is the main culprit. Our cool nights, followed by periods of intense sun, can disrupt fruit set. Low humidity and poor pollination can also contribute.
• How to fix/prevent it: Be patient – fruit set often resumes when temperatures moderate. Provide afternoon shade during heat waves. Keep plants well-watered. Try hand-pollination by gently shaking the plant or using a small brush to transfer pollen.

Aphids

• What it looks like: Clusters of tiny green, black, or white insects on stems and leaf undersides. Sticky honeydew residue and curled or distorted new growth.
• What causes it: Rapidly reproducing sap-sucking insects that thrive in warm weather. Ant colonies may farm them for honeydew.
• How to fix/prevent it: Knock aphids off with a strong spray of water. Encourage natural predators like ladybugs. Use insecticidal soap for heavy infestations. Avoid excess nitrogen fertilizer.

Flea Beetles

• What it looks like: Tiny round holes (shot-hole pattern) in leaves, especially on young seedlings. Small, dark beetles that jump when disturbed.
• What causes it: Small jumping beetles that feed on leaves. They're most damaging to young, vulnerable plants.
• How to fix/prevent it: Use row covers to protect seedlings. Delay planting until plants are larger. Spray with neem oil. Healthy, vigorous plants can outgrow the damage.

Bacterial Spot

• What it looks like: Small, dark, water-soaked spots on leaves and fruit. Spots may have a yellow halo. Infected leaves may turn yellow and drop.
• What causes it: A bacterial disease that thrives in warm, humid conditions. Splashing water spreads the bacteria.
• How to fix/prevent it: Remove and destroy infected leaves. Avoid overhead watering. Improve air circulation by spacing plants properly. Use copper-based fungicides as a preventative measure.

Mountain West Specific Challenges: Our intense sun can sometimes lead to sunscald on peppers, so providing some afternoon shade can be beneficial. The low humidity reduces the risk of fungal diseases, but also means you need to be diligent about watering. Keep a close eye on your plants, especially during periods of extreme temperature swings.

Good companions for banana peppers include tomatoes, basil, carrots, and onions. Tomatoes provide shade and support. Basil repels pests and attracts pollinators. Carrots loosen the soil and improve drainage. Onions deter pests.

Avoid planting banana peppers near fennel or kohlrabi. Fennel inhibits the growth of many plants, and kohlrabi can attract pests that also affect peppers.