Banana Peppers in Zone 4B — Mountain West

Banana Peppers are a rewarding crop for Mountain West gardens. Their mild, sweet flavor is fantastic pickled, roasted, or stuffed. Plus, they're one of the easier peppers to grow, even in our short season, and the cool nights even in summer actually concentrate their sweetness.

Our high altitude and intense sun can be a challenge, along with that short 128-day growing season. But with a little planning and attention to timing, you can absolutely harvest a great crop of Banana Peppers here.

Starting Banana Pepper seeds indoors is the way to go in our zone. Aim to sow seeds from late March through mid April, about 8 weeks before you plan to transplant them outdoors. This gives them a head start against our late spring.

Use seed trays with a good seed-starting mix. Provide consistent warmth (a heat mat is helpful) and plenty of light – a grow light is essential because our spring weather can be unpredictable. Water gently from the bottom to avoid damping off, keeping the soil consistently moist but not soggy.

Remember, our spring can be slow to warm up, so don't rush the process. Patience is key!

Transplanting Banana Peppers outdoors should happen from late May through late June, after the risk of frost has passed. Before you plant them, harden off your seedlings by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the intense UV and cooler nights.

Plant them 18-24 inches apart in a sunny spot with well-draining soil. Keep an eye on the weather forecast around transplant time. A late cold snap can set them back, so be ready to cover them if needed.

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 about once or twice a week, depending on the weather. We don't get much rain here, so irrigation is key.

Use the finger test: stick your finger about 2 inches into the soil. If it feels dry, it's time to water. Aim for about 1-2 inches of water per week, delivered at the base of the plant to avoid wetting the foliage. Our low humidity means foliar diseases aren't usually a big problem, but watering at the base is still best practice.

Underwatering can lead to blossom drop and stunted growth, while overwatering can cause root rot. Drooping leaves can be a sign of either, so check the soil moisture first! A layer of mulch around the base of the plants helps retain moisture and regulate soil temperature, which is especially beneficial in our intense sun.

Banana Pepper plants can get quite prolific, and the weight of all those peppers can cause branches to break. While not strictly necessary, light staking is a good idea, especially if you're aiming for a big harvest.

Install stakes at planting time, placing them a few inches away from the stem. As the plant grows, gently tie the main stems to the stakes with soft twine or plant ties. This will help keep the plant upright and prevent branches from snapping under the weight of the peppers.

Pruning Banana Peppers is pretty straightforward. Pinch off any early flowers that appear before the plant is a decent size. This encourages the plant to focus on vegetative growth first, leading to a stronger, more productive plant later on.

Throughout the season, regular harvesting is the best form of maintenance. As the first frost approaches in mid- September, you can remove any remaining flowers to encourage the plant to put its energy into ripening existing peppers.

You can expect your first Banana Pepper harvest from early August through mid September, about 70 days after transplanting. The peppers are typically ready when they're pale yellow-green and about 6-8 inches long. You can harvest them at any stage from yellow to red, depending on your preference.

To harvest, use sharp pruners or scissors to cut the pepper from the plant, leaving a short stem attached. Avoid pulling the peppers, as this can damage the plant. Regular harvesting encourages continued production, so keep an eye on your plants and pick peppers as they ripen.

As the first frost approaches, harvest any remaining peppers, even if they're still green. They'll ripen indoors if you place them in a paper bag with a ripe apple or banana.

Here are some common issues 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 days can get hot, but the nights stay cool. This temperature swing disrupts pollination. Low humidity can also contribute.
• How to fix/prevent it: Be patient – fruit set usually resumes when temperatures moderate. Provide afternoon shade during heat waves. Water consistently. You can also try hand-pollination.

Aphids

• What it looks like: Clusters of tiny insects (green, black, or white) on stems and leaf undersides. Sticky honeydew and curled or distorted new growth.
• What causes it: Rapid reproduction in warm weather. They're sap-sucking insects, often "farmed" by ants.
• How to fix/prevent it: Strong water spray knocks them off. Encourage ladybugs. Insecticidal soap or neem oil works well.

Flea Beetles

• What it looks like: Tiny round holes (shot-hole pattern) in leaves, especially on young seedlings.
• What causes it: Small jumping beetles that feed on leaves.
• How to fix/prevent it: Row covers protect seedlings. Delay planting until plants are larger. Kaolin clay or neem oil can help.

Bacterial Spot

• What it looks like: Small, dark, water-soaked spots on leaves and fruit. Spots may have a yellow halo. Severely affected leaves may turn yellow and drop.
• What causes it: A bacterial disease that thrives in warm, humid conditions. Although our humidity is low, overhead watering or splashing rain can spread the bacteria.
• How to fix/prevent it: Remove and destroy infected leaves and fruit. Avoid overhead watering and provide good air circulation. Copper-based fungicides can help prevent the spread of the disease.

Mountain West Specific Challenges: Our intense sun can exacerbate blossom drop and flea beetle damage. Consistent watering and providing some afternoon shade can help mitigate these issues.

Companion planting can really give your Banana Peppers a boost. Tomatoes make great companions because they have similar needs and can offer some shade. Basil is another good choice; it repels pests and is said to improve the flavor of peppers. Carrots and onions are also beneficial, as they deter soil pests.

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