Sweet Peppers in Zone 5B — Great Plains

Sweet peppers are a fantastic addition to any Great Plains garden. Their sweet, crisp flavor is a welcome treat, and they're incredibly versatile in the kitchen – perfect for grilling, stuffing, or adding to salads. Plus, there's a real satisfaction in harvesting your own colorful peppers after a long summer of intense sunshine.

Growing sweet peppers in our Zone 5B climate does come with a few challenges, like our extreme temperature swings and the risk of hail. But with careful timing and a little extra attention, you can definitely enjoy a bountiful harvest within our 178-day growing season.

Starting your sweet pepper seeds indoors is essential in our region to get a head start on the growing season. Aim to sow your seeds early to late March, about 8 weeks before you plan to transplant them outdoors. This gives them plenty of time to develop before our weather cooperates.

Use seed trays or small pots filled with a good seed-starting mix. Keep the soil consistently moist – bottom watering works great to prevent damping off. Provide warmth with a heat mat and plenty of light, either from a sunny window or a grow light. Remember, spring in the Plains can be variable, so keep an eye on the temperature in your seed-starting area.

Transplant your sweet pepper seedlings outdoors early May through early June, once the danger of frost has passed. Before transplanting, it's crucial to harden them off. This means gradually exposing them to outdoor conditions for about a week, increasing their time outside each day.

When transplanting, space your pepper plants 18-24 inches apart in a sunny spot with well-drained soil. Keep an eye on the weather forecast around transplant time. A late frost or a hailstorm can set your plants back, so be prepared to cover them if necessary.

Consistent watering is key to growing sweet, thick-walled peppers in our Great Plains climate. Our hot summers and variable rainfall mean you need to pay close attention to your plants' moisture needs. Aim for about 1-2 inches of water per week, depending on rainfall.

Use the "finger test" to check soil moisture – stick your finger about 2 inches deep into the soil. If it feels dry, it's time to water. Water at the base of the plants to avoid wetting the foliage, which can encourage disease in our low-to-moderate humidity. Overwatering can lead to root rot, while underwatering can cause blossom end rot.

Signs of underwatering include wilting leaves and slow growth. Overwatering can cause yellowing leaves and stunted growth. A good layer of mulch, like straw or wood chips, will help retain moisture and regulate soil temperature, especially during our hot summer months.

While not always necessary, providing support for your sweet pepper plants can be beneficial, especially as they become laden with fruit. Some varieties can get quite large and may benefit from staking to prevent branches from breaking.

Tomato cages or individual stakes work well. Install the supports at planting time to avoid disturbing the roots later. As the plants grow, gently tie the stems to the supports with soft twine or plant ties. Wind protection is essential in the Plains, so consider staking even if the plants aren't particularly heavy.

Pruning sweet peppers isn't essential, but pinching off the first few flowers that appear can encourage stronger plant growth and higher overall yields later in the season. This directs the plant's energy into developing a strong root system and foliage.

Simply pinch off the flowers with your fingers or pruning shears. As the season progresses, remove any yellowing or dead leaves to improve air circulation. As the first frost approaches around mid- October, you can remove any remaining small peppers to encourage the larger ones to ripen.

You can expect your first sweet pepper harvest early July through late August, about 65 days after transplanting. The peppers are ready to harvest when they've reached their full size and color for the variety. Sweet peppers get sweeter the longer they ripen on the plant.

To harvest, use pruning shears or a sharp knife 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.

As the first frost approaches in mid- October, harvest any remaining peppers, even if they're not fully ripe. You can ripen them indoors by placing them in a paper bag with an apple or banana. These fruits release ethylene gas, which speeds up the ripening process.

Sweet peppers, like all plants, can face some challenges in the Great Plains. Here are a few common problems and how to address them:

Blossom Drop

• What it looks like: Flowers fall off without setting fruit. Small fruit yellows and drops. Plant looks healthy but produces no fruit.
• What causes it: Temperature stress is the main culprit. Our region's extreme temperature swings, especially during flowering, can cause blossom drop. Nights above 75°F or days exceeding 95°F can prevent fruit set. Low humidity and poor pollination can also contribute.
• How to fix/prevent it: Be patient – fruit set usually resumes when temperatures moderate. Provide afternoon shade during extreme heat. Keep plants well-watered to combat low humidity. Gently shake the plants or use a small brush to hand-pollinate the flowers.

Aphids

• What it looks like: Clusters of tiny soft-bodied insects (green, black, or white) on stems and leaf undersides. Sticky honeydew residue. Curled or distorted new growth.
• What causes it: These rapid-reproducing sap-sucking insects thrive in warm weather. They're often brought in by ants.
• How to fix/prevent it: A strong spray of water can knock them off. Encourage beneficial insects like ladybugs and lacewings. Insecticidal soap works well for heavy infestations. Avoid over-fertilizing with nitrogen, as this attracts aphids.

Sunscald

• What it looks like: White, papery patches on fruit exposed to direct sun. Affected areas may blister and become susceptible to rot.
• What causes it: Intense, direct sunlight on fruit, often after leaves are lost due to over-pruning or disease.
• How to fix/prevent it: Don't over-prune your pepper plants. Use shade cloth during periods of extreme heat. If fruit is already exposed, drape a small piece of row cover over it.

Blossom End Rot

• What it looks like: Sunken, dark brown or black leathery patch on the bottom (blossom end) of fruit. Often affects first fruits of the season.
• What causes it: Calcium deficiency caused by inconsistent watering. This is especially common in the Plains, where we often experience drought/flood cycles.
• How to fix/prevent it: Water consistently! This is the single most effective fix. Mulch heavily to maintain even soil moisture. Avoid over-fertilizing with nitrogen. Remove affected fruit.

Great Plains Specific Challenges: The hot summers, low-to-moderate humidity, and variable rainfall of the Great Plains can make growing sweet peppers challenging. Blossom drop and blossom end rot are more common due to temperature swings and inconsistent watering. Wind can also damage plants, so providing support and wind protection is important. Despite these challenges, with careful attention and proactive measures, you can successfully grow sweet peppers in our region.

Companion planting can be a great way to improve the health and productivity of your sweet peppers.

Good companions for sweet peppers include tomatoes, basil, carrots, onions, and spinach. Tomatoes provide shade, protecting peppers from sunscald. Basil repels pests like aphids and whiteflies. Carrots attract beneficial insects that prey on pepper pests. Onions also deter pests, and spinach provides ground cover, helping to retain moisture.

Avoid planting fennel, kohlrabi, or brassicas (like cabbage and broccoli) near your sweet peppers. Fennel inhibits the growth of many plants. Kohlrabi and brassicas compete for nutrients and can attract pests that also affect peppers.