How to Grow Squash
Cucurbita maxima
Winter squashes (e.g., butternut, acorn) need full sun, rich, moisture-retentive soil, and a long, warm season. Start indoors and plant out after frost into compost-rich mounds with wide spacing. Train vines if space is tight and set developing fruits on tiles or straw. Keep even watering and feed weekly once vines run. Encourage pollinators or hand-pollinate early flowers. Harvest when rinds are hard and stems corky; cure somewhere warm and airy before storing cool and dry.
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
- High-potash liquid feed weekly once fruits form. Rich soil with plenty of compost.
- Winter squash stores for months in a cool, dry place. Cure in sun for 10 days after harvest.
Growing Conditions
- Min. soil temperature
- 12°C+
- Germination temperature
- 20–28°C
Enter your last frost date to see your dates
- Sow indoors
- —
- Transplant out
- —
- First harvest
- —
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Spacing & Planting
| Plant spacing | 90 cm |
| Row spacing | 120 cm |
| Sow depth | 2.5 cm |
| Mature height | 60 cm |
| Mature spread | 180 cm |
Refers to winter squash with vining habits (e.g., Butternut). Summer squash (Courgette/Zucchini) is bushy. Check if variety is bush or vining type.
Pests & Diseases
Pest Slugs and Snails
Identification: Large irregular holes in leaves; slime trails; hollowed-out seedlings; damage to fruit skin where it contacts damp ground
- Apply organic slug pellets (ferric phosphate based) around young plants
- Place developing fruits on tiles, straw, or boards to lift them off wet soil
- Hand-pick slugs at dusk; use beer traps
- Apply ferric phosphate slug pellets around plants
Pest Aphids
Identification: Clusters of green or black insects on growing tips and leaf undersides; sticky honeydew; curled or distorted young leaves
- Blast off with a strong jet of water
- Spray with insecticidal soap
- Encourage ladybirds and hoverflies as natural predators
- Spray with a contact insecticide containing pyrethrins
Pest Red Spider Mite
Identification: Fine stippling on upper leaf surfaces; leaves turn bronze and dry; fine webbing visible between leaves in severe cases
- Mist plants regularly to raise humidity
- Introduce the predatory mite Phytoseiulus persimilis under cover
- Spray with insecticidal soap
- Spray with a miticide or fatty acid-based product
Disease Powdery Mildew Podosphaera xanthii
Symptoms: White, powdery coating on upper leaf surfaces spreading to stems; leaves yellow and die back prematurely; reduced fruit quality
Treatment: Remove badly affected leaves; spray with a sulphur-based fungicide or potassium bicarbonate solution
Prevention: Space plants widely for good airflow; water at the base; avoid overhead watering; choose resistant varieties
Disease Grey Mould (Botrytis) Botrytis cinerea
Symptoms: Fuzzy grey mould on flowers, fruit, and damaged stems; soft, brown rotting patches on developing fruits
Treatment: Remove affected plant parts immediately; improve air circulation; avoid wetting foliage
Prevention: Place fruits on dry surfaces; remove spent flowers; ensure good ventilation around plants
Disease Cucumber Mosaic Virus Cucumber mosaic virus
Symptoms: Mottled, distorted leaves with yellow-green mosaic patterns; stunted growth; misshapen, warty fruits
Treatment: No cure — remove and destroy infected plants to prevent spread
Prevention: Control aphids which spread the virus; remove weeds that harbour it; wash hands and tools between plants
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 Squash?
- Plant Squash 90cm apart with 120cm between rows.
- When can I harvest Squash?
- Squash is ready to harvest approximately 90 days after transplanting.
- Is Squash frost hardy?
- Squash is classified as Tender.
