How to Grow Shelford Giant
Wikimedia Commons
Shelford Giant
Delphinium × elatum 'Shelford Giant'
flowerShelford Giant is a stunning hybrid delphinium cultivar known for its towering spikes of large, semi-double flowers in shades of blue, purple, pink, and white. These majestic perennials can reach 4-6 feet tall and create dramatic vertical interest in cottage gardens and borders. They are prized by florists and gardeners for their impressive blooms and long vase life.
When should you plant Shelford Giant 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.
Example Shelford Giant timeline · Pittsburgh, PA (Zone 6b)
-
Plant Shelford Giant
Around Apr 17Near Pittsburgh's average last spring frost.
-
Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
-
First Shelford Giant blooms
Mid-to-late summerBefore the first fall frost (≈ Nov 8)
Sample dates for Pittsburgh, PA. Sign up to get exact Shelford Giant dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Zones 3-7, with protection in hotter climates
Sign up free to see if Shelford Giant grows in your zone — and get a personalized planting timeline.
Get my Shelford Giant timeline →Growth Stages
Seedling
2-3 weeksTiny seedlings with cotyledons and first true leaves; very delicate and prone to damping off
Start indoors 12-16 weeks before last frost; maintain 70°F soil temperature; provide excellent drainage and air circulation; mist sparingly
Vegetative
4-6 weeksYoung plants develop true leaves and sturdy stems; establish deep root system; foliage is soft green and finely divided
Harden off gradually; plant outdoors after last frost; mulch around base; stake early for tall varieties; pinch back once if you want bushier, shorter plants
Flowering
4-6 weeks (June-July)Tall spikes emerge with densely-packed semi-double flowers ranging from blue to purple, pink, or white; flowers open from bottom to top
Install sturdy stakes or cages immediately; deadhead spent flowers to encourage secondary blooms; water deeply during dry spells; feed with balanced fertilizer
Seed Development
3-4 weeksFlowers fade; seed pods develop along the spike; foliage may decline in vigor
Allow some flowers to go to seed if you want self-sown plants; or cut seed heads for collection; leave some flower stalks standing for winter structure and seed dispersal
Dormancy/Renewal
October-MarchPlants die back to ground level in fall; roots remain alive underground, ready for spring growth
Cut back stems in late fall or early spring; divide clumps every 3-4 years to rejuvenate; mulch lightly in winter in colder zones; avoid winter mulch pile-up on crowns
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
-
Remove infested leaves; use yellow sticky traps; spray neem oil in early morning; encourage parasitic wasps
-
and
Handpick at night; use slug barriers; beer traps; copper tape around planting area; encourage ground beetles
-
Ensure good air circulation; avoid overhead watering; spray with sulfur or neem oil at first signs; remove infected leaves
-
Improve drainage; avoid planting too deep; ensure mulch doesn't touch stem crown; remove infected plants; do not replant delphiniums in same spot
-
Spray with strong water stream; use insecticidal soap; encourage ladybugs and lacewings; neem oil application
Uses
Floral garnish and candying
CulinaryWhile not edible themselves, delphinium flowers are stunning as garnishes for cakes, desserts, and special dishes. Some varieties are food-safe for decoration, though Shelford Giant is typically grown ornamentally. [source]
Cut flowers and arrangements
HouseholdExceptional cut flower with long vase life (7-10 days); a single stem can dominate a floral arrangement. Highly prized by florists and wedding designers for creating vertical drama and height. [source]
Drying for crafts
HouseholdFlowers dry beautifully when harvested at peak bloom; retain color well and are perfect for dried arrangements, pressed flowers, and botanical crafts lasting months or years. [source]
Pollinator attraction
WildlifeTall spikes attract bees, butterflies, and hummingbirds throughout the flowering season; excellent for supporting pollinator populations in gardens. [source]
Garden structure and design
CraftThe dramatic height and color create a key vertical element in cottage gardens, mixed borders, and formal perennial beds; architectural foliage provides seasonal interest. [source]
Harvest Tips
Cut flowers in early morning when lower florets are open but upper ones are still in bud for longest vase life (7-10 days). Cut at an angle with sharp shears, leaving at least 2-3 nodes of foliage on the plant. For seed collection, allow flowers to mature on plant; harvest seed pods when brown and papery, store in cool, dry place. Deadhead regularly to promote secondary blooms.
Fun Facts
- 🌱 Shelford Giant delphinium flowers are light-dependent germinators and actually require exposure to light to germinate; burying seeds too deep will prevent sprouting.
- 🌱 The name 'delphinium' comes from the Greek word 'delphis' (dolphin) because the flower buds supposedly resemble a dolphin's head; these tall spikes were sacred to Apollo in ancient Greece.
- 🌱 Shelford Giant delphiniums were originally hybridized by British plant breeder Frank Bishop in the 1940s at his home in Shelford, creating one of the most iconic delphinium cultivars in horticulture.
Gardening Terms
New to gardening? Learn about terms used in this guide:
Join 30,000 gardeners planning their gardens with LizPlants.
Get your personalized Shelford Giant planting timeline
Tell us your zip code and we'll calculate exactly when to start Shelford Giant 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 Shelford Giant timeline →