Cucurbita pepo, C. maxima or C. moschata (species varies by variety)
Squash is a crop split down the middle by summer and winter types, where the winter half's need for a long, uninterrupted ripening season is the real risk to plan around here.
Squash, pumpkins and courgettes are all closely related cucurbits, but squash specifically splits into two genuinely different crops sharing one name: summer types picked young and eaten fresh, and winter types grown to full maturity for months of storage. Which one you choose changes almost everything else about how you grow it.
Choosing a type
Summer squash has thin skin, is picked young and tender, isn't suited to long storage, and is eaten fresh through summer. Winter squash is left to grow to full maturity, develops a hard skin, and can be stored for months once properly cured. Both come in bush or trailing forms, which matters for spacing more than for the summer/winter choice itself.
Preparing the ground
Choose a sunny spot with rich, moisture-retentive soil that doesn't waterlog. Prepare individual planting holes about 30cm wide and deep, filled with soil mixed with garden compost or other organic matter, or mulchA layer of material spread over the soil around plants to suppress weeds, retain moisture, and improve soil structure as it breaks down. Full definition → the surface for a no-digA growing method that avoids turning the soil over, building fertility instead by adding organic matter on the surface. Full definition → bed. In containers, use a pot at least 45cm wide with peat-freeCompost made without peat, which is harvested from a slow-forming, carbon-storing wetland habitat that peat extraction damages. Full definition → multi-purpose or soil-based compost, and leave plenty of space around it for air circulation, which helps prevent fungal disease.
Sowing
Sow indoors mid-to-late April, one seed on its side, 13mm deep, in a 7.5cm pot at 18-21°C in a heated propagator, covered until germinationA seed sprouting: breaking dormancy and putting out its first root and shoot, given the right warmth and moisture. Full definition →. Outdoors, sow late May or early June, 2.5cm deep, two or three seeds per site protected with a clocheA small, portable clear cover placed over an individual plant or short row to trap warmth and keep off wind, rain and pests. Full definition → or fleeceA lightweight, breathable fabric laid or draped over plants to trap a little warmth and keep off frost, wind and some flying pests. Full definition →, thinned to the strongest seedling.
Planting out
Plant out after the last frost, once hardened off. Space bush varieties 90cm apart and trailing varieties 1.5m apart, a genuinely different spacing depending on habit rather than one figure for the whole crop; Garden Organic gives a tighter 60-90cm range for the same step without distinguishing habit at all, worth knowing if your source disagrees with this one. Protect young plants from slugs and snails, especially in damp weather.
In containers, keep to the same wide spacing rather than crowding pots together: good air circulation around the plant matters as much here as soil prep does, since still, humid air around crowded leaves is exactly what encourages fungal problems later in the season.
Varieties
All three varieties below carry the RHS Award of Garden Merit, a UK-wide award rather than a Scottish one.
RHS also lists 'Harlequin', a compact winter squash on a footprint a fraction of Crown Prince's, and 'Harrier', a butternut-type bred for short growing seasons with a stated ~100-day maturity window (though its own individual plant page shows no AGMThe RHS's Award of Garden Merit: a UK-wide trials award for reliable performance, not a Scotland-specific recommendation. Full definition → badge, despite carrying one on the general list). 'Sunbeam' AGM is functionally identical to Sunburst but tenderer (H1cThe RHS's H1a–H7 scale for how much cold a plant can survive outdoors, H1a being tender indoor-only and H7 hardy anywhere in the UK. Full definition →), so one summer-squash pick covers most of the ground.
★ Our pick for Scotland
Sweet DumplingAGM
Winter squash, small fruit, cream with green stripes, orange flesh
The lowest-risk winter squash to actually finish ripening here.
Why this one: The smallest-fruited winter squash RHS names with AGM, which matters directly here: winter squash needs maximum ripening time before harvest, and a smaller fruit is the more realistic bet against an autumn that can turn before a larger squash finishes colouring and hardening.
Also worth considering
SunburstAGM
Summer squash, patty-pan, small fruit, yellow skin
A summer squash sidesteps the winter-squash ripening risk entirely: picked young and tender, it never needs to reach full maturity at all, the lowest-risk route to a real harvest in an uncertain season.
Crown PrinceAGM
Winter squash, trailing, bluish skin, orange flesh
Included for growers with the space, shelter and season margin to attempt a larger keeper squash: RHS's most prominently listed winter pick, worth the extra ripening risk for the storage payoff a small Sweet Dumpling can't fully match.
Best Squash Varieties for Scotland → compares all named squash varieties head-to-head, with the practical detail that doesn't fit in a summary card.
Care
Water regularly, especially once fruiting starts, and water directly to the soil rather than over the leaves: insufficient moisture, not excess, is what encourages powdery mildew on this crop. Mulch thickly after planting to retain moisture and suppress weeds, leaving a gap around the stem base to prevent rot. Ground-grown plants rarely need feeding; container plants do best with an organic-based, high-potassium liquid fertiliser every 10-14 days once the first fruits start to swell. As winter squash fruit develop, set them on a tile or board to keep them off damp soil and out of rot's way.
Trailing types can sprawl freely, be trained in circles with short canes, or trained vertically up an arch, pergola, trellis or wigwam, with netting to support the fruit; cut back stems that stray too far. Pinch outRemoving the soft growing tip of a stem to stop upward growth and make the plant branch out sideways instead. Full definition → the growing tips of trailing stems once they reach about 60cm.
Harvesting
Summer squash is ready from mid-summer: pick small and tender, regularly, which keeps the plant producing more. Winter squash is judged ready by colour and sound, not size: fully coloured, and sounding hollow when tapped, harvested before the first frost. Cut with at least 10cm of stem still attached; cutting closer leaves a soft spot on the fruit that's prone to rotting in storage.
To store winter squash, let it harden in the sun for one to two weeks, outdoors or under cover, then keep it in a well-ventilated place at 10-15°C, with fruits spaced so they don't touch. Most varieties keep for three months or more; check regularly for deterioration.
How to Store Squash & Pumpkins for Winter → goes deeper on why curing has to happen before storage, and how long each type actually keeps.
Common problems
- Slugs and snails damage young plants.
- Powdery mildew is encouraged by insufficient watering, covered above under Care.
- Grey mould causes fuzzy fungal decay of plant tissue.
See more problems
- Frost damage affects this genuinely tender crop at both ends of the season, at planting and at harvest.
Common questions
Is squash the same as pumpkin?
Botanically, yes: pumpkins are a type of winter squash, though RHS still runs separate guides because the practical concerns genuinely differ: a giant-fruit technique and no AGM varieties for pumpkins, a summer/winter split and six AGM picks for squash. Full sourced breakdown: <a href='/tools/garden-myths/squash/'>Squash Myths →</a>
Why did my winter squash rot in storage?
Almost always the stem was cut too close (leave at least 10cm, or the cut leaves a soft rot-prone spot) or it was picked by size rather than by colour and the hollow-sound tap test, which is what actually signals a hardened, storable skin. Full sourced breakdown: <a href='/tools/garden-myths/squash/'>Squash Myths →</a>
Does powdery mildew on squash mean I've been overwatering?
No: the opposite: insufficient moisture is what encourages powdery mildew on squash, so water regularly and directly to the soil rather than cutting back. Full sourced breakdown: <a href='/tools/garden-myths/squash/'>Squash Myths →</a>
Is squash spacing the same for every variety?
No: bush varieties need about 90cm, trailing varieties around 1.5m, so check which habit your variety has before spacing it. Full sourced breakdown: <a href='/tools/garden-myths/squash/'>Squash Myths →</a>
Sources
2 sources, and what each was used for
- RHS: the summer-vs-winter distinction, soil prep, sowing method and temperature for indoor/outdoor routes, spacing by habit (bush/trailing), watering and the powdery-mildew link to underwatering, mulching, feeding, training on supports, winter-squash ripening and the tile/board technique, harvesting method for both types, curing and storage conditions, six named AGM varieties, slugs, grey mould, powdery mildew, frost damage
- Garden Organic: independently corroborates sowing method, pinching out trailing stems at 60cm, tile-under-fruit technique, and the cut-with-stalk/cure-before-storing method; gives a different germination temperature (13C) against RHS's 18-21C, and a tighter transplant spacing (60-90cm) not split by growth habitA plant's characteristic shape and manner of growth, such as upright, spreading, creeping or bushy. Full definition →, both shown as genuine differences rather than resolved by guesswork