How to Grow Sweet Bell Pepper 'Red Knight'

Wikimedia Commons

Sweet Bell Pepper 'Red Knight'

Capsicum annuum 'Red Knight'

vegetable

Red Knight is a hybrid bell pepper variety bred for early maturity and reliable production of blocky, thick-walled red fruits. This compact, disease-resistant cultivar is ideal for both home gardens and commercial production, typically reaching 24-30 inches tall. It produces abundant peppers that transition from green to deep red when fully mature.

When should you plant Sweet Bell Pepper 'Red Knight' in your zone?

Get a personalized planting timeline — when to start seeds, transplant, and harvest — based on your USDA zone and local frost dates. Free to start.

Get my Sweet Bell Pepper 'Red Knight' timeline →

Example Sweet Bell Pepper 'Red Knight' timeline · Pittsburgh, PA (Zone 6b)

Plant Sweet Bell Pepper 'Red Knight'
Around Apr 17

Near Pittsburgh's average last spring frost.
Tend & protect
Late spring–summer

Watering, feeding, and pest-watch reminders.
Harvest Sweet Bell Pepper 'Red Knight'
Around Jun 16

≈ 60 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Sweet Bell Pepper 'Red Knight' dates for your own zip code.

Growing Conditions

☀️

Sun: Full sun, 8+ hours daily (6 hours minimum, but 8-10 hours optimal for best production and color development)

💧

Water: Consistent moisture; water deeply 1-2 inches per week, more during fruiting. Drip irrigation or soaker hoses preferred to keep foliage dry. Avoid waterlogging and inconsistent watering, which can cause blossom end rot and fruit cracking.

📏

Spacing: 18 inches

📅

Days to maturity: 60-80 days from transplant to first red fruit (green fruit in 45-55 days)

🌱

Planting depth: 0.25 inches for seeds; transplants at soil level

Soil

Type: Well-draining, fertile loamy soil enriched with organic matter

pH: 6.0-6.8

Amendments:

Compost or aged manure (2-3 inches worked in) Balanced fertilizer (10-10-10 or similar) Calcium source (crushed eggshells or gypsum) to prevent blossom end rot Perlite or sand if soil is heavy clay

Growing Zones

Find your zone →

Thrives in zones 5-10 as a warm-season annual; can be grown in zones 2-4 with season extension techniques

2b 3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a 10b 11a 11b

Get my Sweet Bell Pepper 'Red Knight' timeline →

Growth Stages

Germination & Seedling

2-3 weeks

Seeds sprout with two cotyledons; true leaves emerge after 1-2 weeks. Seedlings develop a small root system and 2-4 true leaves.

Start seeds indoors 6-8 weeks before last frost. Maintain soil temperature at 75-85°F for best germination. Provide bright light (14-16 hours daily) under grow lights positioned 3-4 inches above seedlings. Water gently to keep soil moist but not waterlogged. Thin to strongest seedling per cell.

Vegetative Growth

3-4 weeks

Plant establishes strong root system and develops branching stem structure with dark green foliage. Height increases to 6-12 inches; multiple growing points form.

Harden off seedlings gradually over 7-10 days before transplanting outdoors after last frost and soil reaches 60°F. Space 18 inches apart in full sun. Water consistently; apply 2-3 inches compost mulch around base, keeping 2 inches from stem. Pinch first flowers if transplanting late (early July) to encourage stronger plant structure.

Flowering & Early Fruit Set

3-4 weeks

Small white flowers appear in leaf axils. Flowers are self-fertile and bee-pollinated. Fruit begins to set after successful pollination; green pepper fruits appear and enlarge.

Maintain consistent watering and begin regular fertilization every 2-3 weeks with balanced fertilizer (or lower nitrogen once flowering starts). Ensure adequate pollination by allowing bee access or gently shaking plants mid-morning. Support branches with stakes or cages if laden with fruit. Watch for blossom end rot; maintain even soil moisture and apply calcium.

Fruiting & Maturation

4-6 weeks

Peppers enlarge and firm up over 4-6 weeks while still green. Color transition begins; fruits gradually change from green to red over 10-20 days. Fruits develop thick, blocky shape characteristic of Red Knight variety.

Continue consistent watering and fertilization. Remove any diseased or touching leaves to improve air circulation. Mulch to regulate soil temperature and moisture. Provide afternoon shade in regions with intense heat (90°F+) to prevent sunscald. Pick some green peppers if desired to redirect energy to remaining fruit ripening.

Harvest & End of Season

6-8 weeks

Fully mature red peppers are thick-walled, glossy, and deeply colored. Plant may continue producing new flowers if conditions remain favorable, but production slows as temperatures cool.

Harvest red peppers by cutting stem with pruners (not pulling) to avoid damaging plant. Continue harvesting green peppers at any time to encourage new flowering. In fall, as frost approaches, harvest all remaining peppers. Pull plant after first hard frost (28°F or below) or continue indoor growing.

Companion Planting

Plan your garden →

Plant with:

Basil Onion Garlic Carrots Spinach Parsley Marigold Nasturtium

Avoid planting near:

Fennel Kohlrabi Brassicas (cabbage, broccoli, cauliflower) Other capsicum species (cross-pollination concerns for seed saving)

Common Pests

Spray with strong water stream to dislodge; use neem oil or insecticidal soap every 5-7 days if infestation persists. Increase humidity by misting foliage. Introduce predatory mites.
Spray with insecticidal soap, neem oil, or strong water spray. Release ladybugs or lacewings. Avoid excessive nitrogen fertilization.
Use yellow sticky traps to monitor and control. Spray with neem oil or insecticidal soap. Reflective mulch can deter flying insects.
Remove infested fruit and destroy. Apply spinosad-based insecticide. Remove plant debris and weeds that harbor weevils.
No cure; prevent with resistant varieties, crop rotation, and resistant seed. Avoid overhead watering. Remove infected leaves and sterilize tools.
Ensure excellent drainage and avoid waterlogging. Crop rotation (3-year minimum). Apply copper fungicide preventatively in humid conditions.

Uses

🍳

Fresh eating and cooking

Culinary

Red Knight peppers are sweet with thick flesh ideal for eating raw in salads, slicing for vegetable platters, or using in colorful dishes. When fully red, they develop superior sweetness compared to green peppers and can be grilled, roasted, stuffed, or added to stir-fries. [source]

🍳

Roasting and preserving

Culinary

The thick walls of Red Knight peppers make them excellent for roasting whole over flame or under the broiler until charred, then peeling away the skin. They can be preserved by roasting, freezing, canning, or making pepper jelly. [source]

💊

Vitamin C source

Medicinal

Red bell peppers contain approximately 190 mg of vitamin C per 100g (raw), more than twice that of green peppers, supporting immune function and collagen synthesis. The vitamin content is heat-stable for moderate cooking. [source]

🏠

Ornamental garden appeal

Household

Red Knight's compact 24-30 inch height, abundant foliage, and bright red peppers create attractive garden displays. The progression of green to red fruits throughout the season adds visual interest to edible landscapes. [source]

🎨

Seed saving

Craft

Red Knight produces viable seeds that can be saved by allowing fully ripe peppers to age on the plant or stored at room temperature for 2-3 weeks until dry. Seeds stored in cool, dry conditions remain viable for 3-4 years. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

Pick green peppers at any time, typically 45-55 days after transplant, for more tender texture and to redirect energy to other fruits. For red peppers (higher sugar, sweeter flavor), allow fruits to mature fully on plant, turning deep red—typically 60-80 days from transplant. Harvest by cutting stem with clean pruners to avoid damaging branches. Frequent harvesting of mature fruit encourages continued flowering. Peppers ripen faster in warm temperatures (75-85°F); cooler weather slows color development. Harvest all remaining peppers before first frost.

Fun Facts

🌱 Red Knight was specifically bred to mature 1-2 weeks earlier than standard bell pepper varieties, making it ideal for short growing seasons and commercial production targeting early-season markets.
🌱 Bell peppers continue to ripen after harvest if stored at room temperature; a green pepper picked at maturity will gradually turn red over 1-2 weeks indoors, allowing controlled ripening.
🌱 The thick walls of Red Knight peppers indicate high flesh density and lower seed content compared to other varieties, making them superior for roasting and more meaty when eaten raw.

Gardening Terms

New to gardening? Learn about terms used in this guide:

Compost Cultivar Full Sun Germination Hybrid Mulch Pollination Transplant True Leaves

Shop Sweet Bell Pepper 'Red Knight' plants and related plants at Plant Addicts →

Join 30,000 gardeners planning their gardens with LizPlants.

Get your personalized Sweet Bell Pepper 'Red Knight' planting timeline

Tell us your zip code and we'll calculate exactly when to start Sweet Bell Pepper 'Red Knight' seeds, transplant seedlings, and harvest — based on your USDA zone and local frost dates. Includes calendar reminders and printable task lists. Free to start.

Get my Sweet Bell Pepper 'Red Knight' timeline →