How to Grow Imperial Gem Pepper

Wikimedia Commons

Imperial Gem Pepper

Capsicum annuum 'Imperial Gem'

vegetable

Imperial Gem is a compact, ornamental pepper plant that produces small, upright fruits that mature from green to a deep purple-black color. The plant is highly productive and grows well in containers or garden beds, making it popular for both decorative and culinary use. The peppers have a mild to moderately hot flavor and are excellent for fresh eating, cooking, or drying.

When should you plant Imperial Gem Pepper 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 Imperial Gem Pepper timeline →

Example Imperial Gem Pepper timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Imperial Gem Pepper

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Imperial Gem Pepper

    Around Jun 16

    ≈ 60 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Imperial Gem Pepper dates for your own zip code.

Growing Conditions

☀️
Sun: Full sun, 8+ hours daily for best fruiting and color development
💧
Water: Consistent moisture; water deeply 1-2 times weekly. Allow soil surface to dry slightly between waterings. Reduce watering slightly once fruits set to intensify flavor and color.
📏
Spacing: 18 inches
📅
Days to maturity: 60-90 days from transplant to first mature fruit
🌱
Planting depth: 0.25 inches for seeds; transplants should be at same depth as container

Soil

Type: Well-draining loamy soil with good organic matter
pH: 6.0-6.8
Amendments:
Compost Aged manure Perlite or sand for drainage Balanced fertilizer (5-10-10 NPK)

Growing Zones

Find your zone →

Thrives in zones 5-10; can be grown as annual in cooler zones 3-4 with protection or indoor starting

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

Sign up free to see if Imperial Gem Pepper grows in your zone — and get a personalized planting timeline.

Get my Imperial Gem Pepper timeline →

Growth Stages

1

Seedling

3-4 weeks

Seed germinates in 7-14 days. Young plants develop first true leaves and establish root system.

Keep soil warm (70-80°F) and moist. Provide grow lights 14-16 hours daily. Thin to strongest seedling if multiple sprout.

2

Vegetative

4-6 weeks

Plant develops multiple stems and leaves, creating a bushy mound 12-18 inches tall. No flowers yet.

Harden off transplants gradually before moving outdoors. Plant after last frost when soil is warm (60°F+). Pinch growing tip at 6 inches to encourage branching.

3

Flowering

3-4 weeks, overlapping with fruiting

Small white or pale lavender flowers appear at branch tips. Flowers are self-pollinating but benefit from bee activity.

Ensure consistent watering and full sun exposure. Avoid high-nitrogen fertilizer which promotes excessive vegetative growth. Light misting can improve pollination.

4

Fruiting

3-6 weeks per fruit set

Peppers form and enlarge, starting green and gradually turning deep purple-black when ripe. Compact plant heavily laden with upright fruits.

Continue consistent watering and feeding. Apply balanced fertilizer every 2-3 weeks. Support branches if heavily loaded with fruit. Harvest some immature peppers to encourage more production.

5

Harvest/Maturity

Until first frost (6-10 weeks of continuous harvest)

Peppers reach full deep purple-black color and firm texture. Plant continues producing throughout growing season until frost.

Harvest regularly to encourage continued production. Use sharp pruners to avoid damaging stems. Leave some peppers on plant for ornamental effect if desired.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Fennel Kohlrabi Cabbage (can attract same pests)

Common Pests

  • Spray with water to dislodge; use insecticidal soap or neem oil every 5-7 days. Increase humidity around plants.

  • Remove infested fruits immediately. Use row covers on young plants. In severe cases, apply spinosad or pyrethrin-based insecticide.

  • Spray with strong water stream; use insecticidal soap or neem oil. Encourage beneficial insects like ladybugs.

  • Use yellow sticky traps. Apply neem oil or insecticidal soap weekly. Reflective mulch can deter them.

  • Maintain consistent soil moisture and calcium levels. Apply lime if soil is deficient. Mulch to regulate moisture.

Uses

🍳

Fresh eating and cooking

Culinary

Imperial Gem peppers offer a mild to moderately hot flavor that's versatile in the kitchen. They can be eaten raw in salads, stuffed, roasted, grilled, or used in stir-fries and salsas. [source]

🌿

Container and landscape ornament

Ornamental

The compact, bushy growth habit and prolific deep purple-black fruit production make Imperial Gem highly ornamental. It's ideal for decorative pots on patios, balconies, and garden borders. [source]

🏠

Drying and preservation

Household

Imperial Gem peppers dry well and can be stored for months. Dried peppers can be ground into powder, used in spice blends, or rehydrated for cooking. [source]

🍳

Pepper powders and spice blends

Culinary

Dried Imperial Gem peppers can be ground into specialty pepper powders or combined with other spices to create custom blends for seasoning and cooking. [source]

🦋

Pollinator attraction

Wildlife

The abundant white-lavender flowers attract bees and other pollinators, supporting garden biodiversity while improving fruit set through enhanced pollination. [source]

Harvest Tips

Harvest peppers at green stage for milder flavor, or wait until they turn deep purple-black for fuller, sweeter flavor with slight heat. Use sharp scissors or pruners to cut peppers from the stem rather than pulling. Regular harvesting encourages more production. Peppers can be used fresh, roasted, dried, or processed. The plant will continue producing until the first frost.

Fun Facts

  • 🌱 Imperial Gem peppers start green and gradually develop their distinctive deep purple-black color as they mature, sometimes taking 2-3 weeks to fully color after reaching mature size.
  • 🌱 The compact growth habit (12-18 inches tall) makes Imperial Gem one of the best pepper varieties for container gardening, thriving even in 5-gallon pots on sunny patios.
  • 🌱 Imperial Gem is descended from ornamental pepper breeding programs but produces fully edible, flavorful fruit—it successfully bridges the gap between decorative and culinary peppers.

Gardening Terms

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

Join 30,000 gardeners planning their gardens with LizPlants.

Get your personalized Imperial Gem Pepper planting timeline

Tell us your zip code and we'll calculate exactly when to start Imperial Gem Pepper 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 Imperial Gem Pepper timeline →