Crop type: Pumpkins
Cucurbita maxima ‘Atlantic Giant’
Common name: Pumpkin ‘Atlantic Giant’
Crop slug: pumpkins
This Allotment Pro editorial draft summarises the cited RHS cultivar profile and its linked crop guidance. Check the sources and adjust cultivation decisions for local conditions.RHS cultivar profile
1 - Overview
‘Atlantic Giant’ is an accepted Cucurbita maxima winter squash famous for producing some of the world's largest pumpkins. Its vigorous trailing vines can extend to about 5m. Mature fruits vary in form, including broadly rounded and egg-shaped examples, and can exceed 1.8m in diameter under competition conditions. They have red-orange to orange skin and bright-orange flesh.
The cultivar is grown primarily for exceptional size and competition display. Its flesh can be watery, but remains usable for stocks and soups. Give one plant extensive fertile ground, steady warmth and abundant water, then retain one ideally placed fruit if maximum weight is the aim.
2 - Size
- Ultimate height
- 0.5–1 metre
- Ultimate spread
- 4–8 metres
- Time to maturity
- one year
- Typical vine length
- up to about 5m
- Fruit
- exceptionally large, sometimes more than 1.8m across
Reserve a dedicated bed and ample clear ground around the selected fruit. The enormous pumpkin must remain flat and cannot be supported on a trellis. Position a broad dry board beneath it early, before its weight makes movement unsafe.
3 - Growing conditions
- Suitable soils
- Loam or sand
- Moisture
- Moist but well drained, or well drained
- Preferred pH
- Acid or neutral
Prepare a deep planting pocket with generous compost or well-rotted manure. Maintain even moisture without waterlogging and mulch after the soil warms. Once fruit begins to swell, feed regularly with a high-potassium fertiliser. Competition growth requires uninterrupted water and nutrition as well as a large canopy of healthy leaves.
4 - Position and hardiness
- Light
- Full sun
- Aspect
- South- or west-facing
- Exposure
- Sheltered
- Hardiness
- H2
Choose the warmest sheltered position available. This tender annual tolerates low temperatures only above freezing, so raise it under cover and plant outside after the final frost. A long sunny season is essential for both fruit size and skin maturity.
5 - Colour and seasonal interest
Vigorous green trailing vines carry large lobed leaves and golden-yellow flowers. The defining autumn fruit is colossal, broadly rounded or somewhat egg-shaped, with broad shallow ribbing and red-orange skin over bright-orange flesh. The illustration should make its massive scale and slightly irregular giant form unmistakable while avoiding people, measuring devices, prize rosettes or text.
6 - Botanical details
- Family
- Cucurbitaceae
- Native to Great Britain and Ireland
- No
- Foliage
- Deciduous
- Habit
- Trailing
- Name status
- Accepted
Genus
Cucurbita includes climbing and trailing annual plants native to Central and South America, with palmately lobed leaves, separate golden-yellow flowers and fleshy fruits cultivated for food and display.
Safety
Do not eat or give pets any fruit that tastes unusually bitter. Discard bitter fruit and remove the plant because harmful cucurbitacins may be present. Use gloves if rough, prickly growth irritates skin.
7 - How to grow
Cultivation
Sow indoors from March to May in seed compost, placing seed on its side 1cm deep at 18–21°C. Provide bright light, harden the plant off and set it into fertile, moisture-retentive but well-drained soil after frost.
Water deeply and feed with a high-potassium fertiliser once fruits swell. Choose one strong early fruit on a healthy vine and remove all later competitors for giant growing. Preserve abundant foliage on both sides of it. Harvest before frost when the skin has hardened, cutting with at least 10cm of stalk attached.
Propagation
Propagate by seed and retain one vigorous plant per generously spaced position.
Suggested locations
- Dedicated giant-pumpkin bed
- Large allotment or vegetable plot
- Competition growing area
- Productive wildlife garden with extensive open ground
Pruning
Routine pruning is unnecessary. For giant fruit, remove unwanted fruitlets while retaining the vine and healthy leaf area needed to feed the chosen pumpkin.
Pests
The profile records it as generally pest-free. Protect seedlings from slugs and snails and inspect beneath sprawling foliage.
Diseases
May be susceptible to grey mould and powdery mildew. Water at soil level, avoid drought stress, maintain air circulation and remove decaying material.