Growing at Glebelands

Squash (Cucurbita species)

Family (for rotation): Cucurbits
6-8 sds/g. 1000 sds = 200-500g.
Seed can last 6 yrs.
Sowing depth 2cm, min sowing temp 13ºC, seedling emergence 5+ days

Types: - lots! - have included details of some specific varieties we have grown at Glebelands

Summer Squash (C. pepo) Mainly courgettes, but also Patty Pan types – can be white, green or yellow (eg Sunburst F1) (38-52 days) Can be picked tiny with blossom still attached, or teacup size

Acorn Squash (C. pepo) Medium-small ribbed squashes, best eaten immediately after picking, and within 3 mths of harvest, eg Table Ace (85 days): medium small, up to 1kg with black-green colour. Semi-bush habit, early, high yielding 5-7/plant. Can be picked small as summer squash or left for autumn. Good baked.

Buttercup/Kabocha Squash (C. maxima) Small to medium-large sized, round but slightly flattened, with thick, dry, orange flesh. Buttercup type has a “button” on the blossom end. Harvest after stem browns and becomes “corky”. Very dry at harvest, sweeter after a few weeks. Important to store in dry conditions.
Buttercup (95 days): dark green, medium small (1-2 kg) fruits which store well and taste great. Av yield 3-4/plant
Marina di Chioggia: medium-large globe shaped, with knobbly grey-green skin. Stores well with flavour improving with age

Spaghetti Squash (C. pepo) (88 days)White to yellow skinned, oblong, smooth, medium sized (1½-2.2 kg), with purposely stringy mildly sweet “spaghetti” flesh. Av yield 4-5/plant

Delicata/Sweet Dumpling Squash (C. pepo) (100 days) Pale yellow or cream coloured edible skin, often with green stripes, sweet flesh, best within 4 mths of harvest. Small fruits which can be baked whole or stuffed. Av yield 8-10/plant

Butternut Squash (C. moschata) (105 days) Usually cylindrical with a bulbed end (Butternut type), or can be other shapes like the flat “cheese” type. Usually tan skin. Has the longest storage potential of all squashes, but need a long growing season, which can be difficult in the UK. If possible, use cultivars specially bred for here. Can weigh over 2kg. Av yield 4-5/plant

Hubbard Squash (C. maxima) Medium to large, round to oval, with a neck at the stem end, and can be ribbed. Skin colour can be blue, dark green or orange, while flesh is medium dry and orange. Medium to long storage. Harvest when stem large & corky.
Red Kuri (92 days) Teardrop or onion shaped fruits, 2-3 kg, with nutty flavour, also known as Orange Hokkaido. Av 2-3/plant
Blue Ballet (95 days) Smooth-skinned, blue-grey fruits, 2-2.7kg, with sweet orange flesh. Stores well. Av 2/plant

Pumpkins (C. Pepo) - term usually used for winter squash with orange skin when mature, eg Baby Bear (105 days) A mini pumpkin (0.6-1 kg) with slender handles. Av 8/plant. To be harvested before frost or after 1 or 2 light frosts Lady Godiva (110 days) Grown for hull-less seeds

squash flower Sowing and planting

Squash prefer warm conditions, so a reasonably sunny & sheltered is preferable. They need a rich fertile soil, but it is possible to make a planting place by digging a hole 1ft deep & 18” square and mixing well rotted manure or compost into the soil as hole is refilled.

Too rich soil can lead to rampant growth at the expense of fruit, but this growth is good for suppressing weeds (can be grown through a weed-suppressing mulch to clear new plot).

At Glebelands, we sow in large modules mid-end April, and transplant at 4-5 weeks (usually gently transplanting from smaller to larger modules to save space).This enables plants to be started even when conditions outside are not suitable for sowing there, and so gives a longer growing season with better chance of fuit ripening before autumn.

Sow at 15-18°C, germination in 5-14 days. Seeds will rot if conditions too cold or wet. Ensure plants are kept warm and in even light, and be careful they don’t become too soft or leggy as this makes them much more vulnerable to slugs and wind when transplanted.

Ideally harden off before planting at 2-3 leaf stage, when they have two strong leaves & a 3rd just developing. The fragile stems can easily be eaten overnight by slugs or snapped by wind just after transplanting, so avoid planting if wind forecast (or put up temporary windbreaks) and establish an even tilth with no clods which could shelter slugs. Also ensure plants aren't in any hollows, which could make condtions too wet, or on any mounds, which could make conditions too dry for them.

Best planted at 5-6ft spacings. At Glebelands we plant 3ft apart along one row down middle of bed, in beds 5 ft apart. Aim for basically one plant/1-2 m². Ideally do several weed strikes before planting to get weed seeds to germinate – also, the wide spacings allow easy cultivation (with tractor or hand hoeing) after transplanting. Lots of space between plants means lots of weed germination until plants grow up, but also allows for lots of cultivation


Plants will grow very quickly in sunny conditions. Water generously in dry spells, particularly when fruit forming – plants are shallow rooted, so thorough watering 1-2 times per week is better than occasional soaking. If possible, concentrate water at centre of plant, though trailing stems often make own short roots which also take up water & nutrients.

Undersowing: Growers such as Ian Tollhurst and Alan Schofield (see Links page), undersow squash with legumes such as Red Clover or Yellow Trefoil. This means that when the plants die off in October, there is already a "green manure" in place - it can be very difficult to establish any kind of winter soil cover in the autumn, when condtions can be wet and cold, but this method means the cover is already in place and can grow on until the following spring or summer.

The undersowing must be carried out when the main crop is well established (to avoid competition), but before the main crop becomes too rampant (so the undersown crop can get established). So,like comedy, timing is of the essence.

It is also important to get a clean (ie weed free) seedbed for any green manure sowing and this can very much depend on weather conditions. We have successfully undersown squash with yellow trefoil, usually broadcast around the plants when they are at the 5-7 leaf stage, and after several weed strikes. The trefoil then continues to grow into the autumn after the squash plants have died back, providing the soil with protection over winter against leaching etc, then begins re-growing in spring as temperatures rise, fixing Nitrogen at a period when it is usually too early for a spring-sown green manure to be established.

We have also undersown Courgettes, Kale and Chard, with varying degrees of success, in the same way - this spring (2009), yellow trefoil is thriving sown beneath Kale, also thriving. The relatively low-growing trefoil appears not to mind getting walked on, so is suitable for crops which are being regularly picked, such as courgettes.


Some summer squash varieties can be cut very small eg Patty Pan at teacup size or smaller.

Winter squashes & pumpkins need most of the season to grow to their full size and do not ripen until late summer – then their skin gradually hardens and their colour changes. If using fruit straight away, can pick at any stage, but if planning to store, best to leave on plant for as long as possible.

Can pull back leaves to allow sun to ripen fruit, but can delay picking while nights remain above freezing. Can wait until a light frost which will cause foliage to collapse before harvesting, or can wait until foliage starts to die back naturally at beginning of Oct. A hard frost will damage fruits.

Harvest in dry weather, and keep rain off stalk stubs after cutting. Can leave a long piece of stem as a handle and to stop fruit rotting.

Curing: Most varieties need curing to completely harden the skin (Acorn are an exception) Leave in a warm dry place for several weeks to ripen fully, before storing at 7-10°C. Some varieties can be stored for 6 months, but keep checking regularly for rots.