VegetablePepper
Keystone Resistant Giant Pepper
Keystone Resistant Giant Pepper is an open-pollinated heirloom sweet pepper that produces enormous 4-inch fruits with remarkably thick, sturdy walls on compact 18, 24 inch plants. Ready to harvest in 70, 79 days from transplant, this Capsicum annuum variety grows reliably across hardiness zones 4, 11 and performs equally well in garden beds, raised containers, or greenhouses. Its fruits shift from green to deep red as they mature, delivering consistent harvests of sweet, heat-free peppers throughout the season while resisting three major pepper diseases including Tobacco Mosaic Virus.
Photo © True Leaf Market
Growing Conditions
USDA Zone
4-11
Sunlight
Full Sun
Water
Moderate
Soil
Well-drained, Fertile Loam With Organic Matter
Growth Stats
24 in
Height
TypeUpright
Spacing
24
Plant Profile
Sunlight
Full Sun
Water
Moderate
Zones
4-11
Size
24in H x ?in W
Growth
—
Care
Moderate
Hover over chart points for details
Highlights
These aren't ordinary peppers. The fruit reaches a hefty 4 inches across with walls so thick they're perfect for stuffing, grilling, or slicing raw. The plants stay manageable at under 2 feet tall, making them suitable for tight spaces or containers, yet they produce abundantly from mid to late summer. Open-pollinated genetics mean you can save seeds year after year, and the built-in disease resistance to Tobacco Mosaic Virus, Bacterial Leaf Spot, and Ph means fewer headaches and stronger plants.
Common Uses
These peppers shine as stuffed peppers, where their thick walls hold fillings beautifully without collapsing. The generous cavity is equally suited to grilling whole or halved, roasting until the skin softens, or slicing raw into salads and slaw. Their sweetness and substantial structure make them excellent candidates for freezing or preserving.
Growing Timeline
No timeline data available yet for this variety.
Care Instructions
Start Indoors
Start seeds indoors 6, 8 weeks before your anticipated last spring frost date. Sow seeds 1/4 inch deep in seed-starting mix kept at 70, 80°F; germination typically occurs within 7, 14 days. Keep seedlings under grow lights and maintain consistent moisture without waterlogging.
Transplant Outdoors
Harden off seedlings over 7, 10 days by gradually exposing them to outdoor conditions. Transplant outdoors once nighttime temperatures consistently reach 50°F or higher and all danger of frost has passed. Space plants 24 inches apart in rows 36 inches apart, planting at the same depth they grew in containers.
Harvesting
Peppers reach full maturity 70, 79 days after transplanting. Harvest at any stage, from immature green to fully ripe red, depending on your preference. Ripe fruits will feel firm to the touch and exhibit a glossy finish, and the walls will have thickened substantially. Use pruners or a sharp knife to cut peppers from the plant rather than twisting them off, which can damage branches.
Pruning
Since these peppers grow in an upright habit and remain relatively compact at 18, 24 inches, minimal pruning is needed. Pinch off early flower buds if plants seem small or leggy at transplant time to encourage branching and stronger growth before fruiting. Remove any yellowed or diseased leaves as they appear to improve air circulation and reduce disease pressure.
Growing Calendar
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Companion Planting
Pests & Diseases
Ecology & Traits
Edible
Scientific Classification
Capsicum annuum
Family
Solanaceae
Genus
Capsicum
Growth Habit
Upright
Native Status
L48 (NI)HI (I)PR (I)VI (I)