How to Grow Marrow
Cucurbita pepo
Marrows are warm-season cucurbits for full sun and rich, moisture-retentive soil. Start indoors late spring and plant out after frost, or direct sow under cloches. Water deeply and feed regularly once flowering. Allow fruits to mature on the plant; support on a tile or straw to keep dry. Pick when well-sized but before skin hardens fully for cooking; leave longer for exhibition or stuffing. Mulch to hold soil moisture and keep leaves off damp ground.
When to Start
Start seeds indoors 4 weeks before your last frost date. Transplant outdoors once night temperatures stay above 10°C and soil has warmed to at least 12°C.
Don't know your frost date? Find it here →
Growth Stages
Approximate days from start
Care Essentials
- Once flowering begins, feed every two weeks with a high-potash liquid fertiliser. Before planting, enrich the soil generously with well-rotted compost or manure — marrows are hungry plants.
- Marrows need full sun, rich soil, and consistent moisture. Water deeply at the base each week and mulch well to retain moisture. In cool summers, hand-pollinate flowers to improve fruit set.
Growing Conditions
- Min. soil temperature
- 12°C+
- Germination temperature
- 20–28°C
Pet Safety
- Sow indoors
- —
- Transplant out
- —
- First harvest
- —
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Spacing & Planting
| Plant spacing | 75 cm |
| Row spacing | 85 cm |
| Sow depth | 2.5 cm |
| Mature height | 40 cm |
| Mature spread | 120 cm |
Marrows are trailing plants that need plenty of room. Train along the ground or over a compost heap. Allow at least 1 square metre per plant.
Pests & Diseases
Pest Slugs and Snails
Identification: Holes in leaves and stems, particularly damaging to young plants
- Physical barriers around young plants
- Beer traps
- Hand picking at dusk
- Slug pellets - use sparingly
Pest Aphids
Identification: Small insects clustering on undersides of leaves and new growth
- Insecticidal soap
- Strong water spray
- Encourage natural predators
- Approved systemic insecticides
Disease Powdery Mildew
Symptoms: White powdery coating on leaves, more common late in season
Treatment: Remove affected leaves, improve ventilation
Prevention: Good air circulation, water at soil level, avoid overcrowding
Disease Grey Mould (Botrytis) Botrytis cinerea
Symptoms: Fuzzy grey mould on fruits and stems
Treatment: Remove affected parts, improve growing conditions
Prevention: Good air circulation, remove damaged fruits promptly
Growing Conditions
| Min. soil temperature | 12°C |
| Germination temperature | 20–28°C |
| Base growth temperature | 10°C |
| Min. daylength to start | 10h |
| Photoperiod sensitivity | day neutral |
Frequently Asked Questions
- How far apart should I plant Marrow?
- Plant Marrow 75cm apart with 85cm between rows.
- When can I harvest Marrow?
- Marrow is ready to harvest approximately 45 days after transplanting.
- Is Marrow frost hardy?
- Marrow is classified as Tender.
