How to Grow Winter Squash from Seed
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Learning how to grow winter squash from seed starts with timing and spacing. Sow once the soil is warm and frost is past, bury the seeds about an inch deep, thin to one or two vines in each spot, and give each vine as much room as its type needs. The four university extension pages this guide draws on agree on the basics. They differ on exact spacing, so the table below shows each figure with its source.
The pages come from Arkansas, Saskatchewan, Illinois and Pennsylvania, so the climates they describe range from warm southern summers to cool northern ones. Check your local extension calendar before you pick a sowing date.
Quick answer
- Sow after the soil warms. Arkansas uses 62 degrees Fahrenheit, Penn State 65 degrees Fahrenheit and Saskatchewan 18 degrees Celsius as the marks.
- Plant seeds about an inch deep. Saskatchewan’s direct-sow rule is 2 cm, which is about the same.
- Thin to one strong plant, or to one or two per hill, once the seedlings are up.
- Match spacing to the vine type, since vining types need far more room than bush types.
Wait for warm soil and frost-free weather
Winter squash is a warm-season crop, and the four pages agree that cold soil stops it. Illinois says the seeds do not germinate in cold soil and that frost injures the seedlings. Arkansas says to plant seed directly in the garden once the danger of frost has passed and the soil has warmed above 62 degrees Fahrenheit. Penn State sets the germination floor at 65 degrees Fahrenheit, and Saskatchewan says seeds can go in once the soil reaches at least 18 degrees Celsius.
Timing also changes by region. Penn State says direct seeding in Pennsylvania generally falls between late May and early June, depending on the region. Saskatchewan adds that winter squash prefers warm soil and that plastic mulch, tunnels or crop covers can help it grow. Those covers should come off once the flowers open, a point covered below.
Sow about an inch deep, two to four seeds per spot
Depth is the simplest rule on the list. Illinois and Penn State both give one inch, and Arkansas says to cover the seed one inch deep. Saskatchewan’s direct-sow rule is 2 cm, which it also describes as one inch, so the four pages are consistent once the units are converted.
The number of seeds per spot depends on the type. Arkansas says that for single-plant production, two or three seeds go 24 inches apart, or three or four seeds go in hills 48 inches apart. Illinois gives four or five seeds per hill for vining types and one or two seeds per foot of row for bush types. Saskatchewan advises three or four seeds per spot. Thinning comes after emergence. Arkansas says to thin to one vigorous plant, or to no more than two plants per hill, once the plants are two to three inches high. Illinois says to thin each vining hill to the best two or three plants once they are well established, and to thin bush types to one plant every three feet.
Set spacing by vine type
The table below puts each page’s spacing figures side by side. Read it as a range, because the vine type decides most of the answer. Illinois says winter squash is adapted to a wide variety of conditions and that the plants are vining types unless a listing says otherwise. It also notes that some varieties are sold under the name pumpkin, and that the difference between squash and pumpkins is mainly in what you call them. Check the vine habit on the seed packet rather than the name.
| Source | Vining types | Bush types | Rows |
|---|---|---|---|
| Arkansas (FSA 6078) | 2 to 4 feet apart, with two or three plants per hill | Not stated separately | 48 inches apart |
| Saskatchewan (USask) | 36 to 48 inches apart within the row | Not stated separately | 48 to 72 inches apart |
| Illinois | 5 to 6 feet between hills; at least 50 to 100 square feet per hill | One plant every 3 feet | Vining 7 to 12 feet; bush about 5 feet |
| Penn State | 4 to 5 feet apart | 3 to 4 feet within rows | Vining 6 to 8 feet; bush 4 to 6 feet |
Illinois states the difference plainly: vining types need at least 50 to 100 square feet per hill, while the bush and semi-vining types can be grown in smaller gardens. Saskatchewan adds that squash vines need a lot of space. If your bed is small, choose a bush variety before you start the seed. For a bed that fits this kind of planting, vegetables to plant in raised beds lists other crops to plan around.
Start seedlings indoors without stressing the roots
Saskatchewan gives the most detail on indoor seedlings, and its main warning is about timing. Winter squash does not like root disturbance from transplanting, so seedlings should not start too early. The page says seedlings should be only 10 to 14 days old when they go out, with the cotyledons emerged and only one or two true leaves. Start them about two to three weeks before transplanting.
For the sowing step, Saskatchewan suggests two seeds about one centimeter deep in each Jiffy-7 or container, then thinning to the strongest plant after the first true leaves appear. It recommends soaking the Jiffy-7 first in warm water, and covering the pot with plastic or a dome until germination. Once the seeds are up, remove the plastic. At 24 degrees Celsius, seeds germinate in five or six days, and the page says seedlings need at least 14 hours of light each day. Keep the soil moist like a damp sponge, but not soggy.
Before planting out, harden the seedlings. Saskatchewan says to move them outdoors into a sheltered, frost-free spot at least three days before transplanting, and to transplant once day and night temperatures are warm. The page also says not to fertilize newly planted seeds or young emerging seedlings, so feeding waits until after the plants go out.
Feed and water the young plants
Penn State says winter squash is a heavy feeder, particularly of nitrogen and potassium. The same page warns that too much nitrogen can delay fruit maturity and reduce storage quality, so balanced fertility is the goal. Arkansas advises working compost or well-rotted manure into the soil before planting. Saskatchewan says the crop grows best in rich, well-draining, moist soil.
Water matters from the start. Arkansas notes that squash plants are shallow-rooted and need steady soil moisture at every stage of growth. Saskatchewan’s seedling advice is the same rule in miniature: keep the mix moist and avoid soggy conditions. Penn State adds that squash is sensitive to waterlogging, which is why raised beds or sandy loams work better than heavy clays. If the bed is still in the planning stage, how much soil a raised bed needs is the next question to settle.
Pollinators, covers and the flowering stage
Squash has male and female blooms and needs bees for pollination, according to Arkansas. Saskatchewan says covers and tunnels must come off as soon as flowers appear, so that bees and other pollinators can reach the flowers. That makes a cover a short-term aid: use it for early growth, then remove it when the first flowers open.
Saskatchewan also says winter squashes can grow in containers outdoors, but this is less practical because of their large size, unless a bush type is used. Illinois says bush and semi-vining types suit smaller gardens. Arkansas notes that vine crops do not transplant well once the plants are very large, so a seedling should go out while it is still young.
Harvest, cure and store the squash
Penn State says most varieties are harvested from September to October, before the first hard frost, and it describes the ideal scenario as letting the fruit ripen completely on the vine. Illinois describes the harvest stage the same way: winter squash is eaten when the seeds have matured fully and the skin has hardened into a tough rind. Saskatchewan notes that cultivars for direct seeding should mature in 80 days or less, and that winter squash as a crop needs 85 to 115 days depending on the type. Count back from your first frost date when you pick a variety.
Curing comes next. Penn State says the squash can be left in the field for about seven to fourteen days when conditions are favorable, or lifted off the ground and laid out in a dry, well-ventilated spot. Once cured, a squash that is unmarked and intact can go into long-term storage in a cool, well-ventilated area, with temperatures from 50 to 60 degrees Fahrenheit and relative humidity from 50 to 75 percent, which the page says prevents shriveling. Keep the storage area above 50 degrees Fahrenheit, because chilling injury follows exposure to lower temperatures. The same page gives a storage window of two or three months for most squash, shorter for acorn and longer for Hubbard.
Mistakes to avoid
- Starting seedlings too early. Saskatchewan says winter squash does not like root disturbance, so seedlings should be 10 to 14 days old at planting.
- Sowing into cold soil. Illinois says seeds do not germinate in cold soil and frost injures the seedlings.
- Planting vining types in a small bed. Illinois says vining types need at least 50 to 100 square feet per hill.
- Feeding young seedlings too early. Saskatchewan says not to fertilize recently planted seeds or young emerging seedlings.
- Applying too much nitrogen. Penn State says excess nitrogen can delay maturity and reduce storage quality.
How we chose
We limited this guide to university and extension pages that give direct seeding rules for winter squash. We opened each page with curl on 2026-10-23 and read the seeding passages. Four pages gave usable text: Arkansas, Saskatchewan, Illinois and Penn State. Other pages were tried and gave no answer. The South Dakota State, Kentucky, North Dakota State and Minnesota pages returned no response, and two Michigan State pages returned a bot-protection screen instead of an article. The NC State vegetable handbook was opened and not cited. Each figure in the table is attributed to the page that gave it.
What we could not verify
The four pages do not agree on exact spacing, sowing depth or the soil temperature to sow at, so the guide gives each figure with its source rather than averaging them. They also do not give one days-to-harvest number for all winter squash, because the range depends on the cultivar.
What the sources do not say
None of the four pages names a cultivar for a particular region, and none gives a pot size for seedlings. They do not give a feeding rate for squash grown in containers, and they do not say how deep a bed needs to be for winter squash. The pages say little about the seedling stage beyond the Saskatchewan rules, so this guide does not add to them.
Frequently asked questions
When is the soil warm enough to sow winter squash?
The sources give three marks. Arkansas says above 62 degrees Fahrenheit, Penn State says at least 65 degrees Fahrenheit for germination, and Saskatchewan says at least 18 degrees Celsius. Penn State’s 65 degrees is the most cautious of the three.
How deep should winter squash seeds go?
About one inch. Illinois and Penn State both give that depth, Arkansas says to cover the seed one inch deep, and Saskatchewan gives 2 cm, which it describes as one inch.
How many seeds should go in each spot?
It depends on the vine type. Arkansas says two or three seeds 24 inches apart, or three or four seeds per hill 48 inches apart, for single plants. Illinois gives four or five seeds per hill for vining types, and one or two seeds per foot of row for bush types.
Can winter squash be started indoors and moved outside?
Yes, according to Saskatchewan, which says to start seedlings two to three weeks before transplanting and to plant them out at 10 to 14 days old. Harden them off in a sheltered, frost-free spot for at least three days first.
Can winter squash grow in a container?
Saskatchewan says it can grow in containers outdoors, but calls that less practical because of the plant’s size, unless a bush type is chosen. Illinois says bush and semi-vining types fit smaller gardens better than vining types.
Sources
- https://www.uaex.uada.edu/publications/pdf/FSA-6078.pdf (opened 2026-10-23)
- https://gardening.usask.ca/gardening-advice/gardenline-nested-pages/food-plant-pages/vegetables/winter-squash.php (opened 2026-10-23)
- https://extension.illinois.edu/gardening/winter-squash (opened 2026-10-23)
- https://extension.psu.edu/pumpkins-and-winter-squash-in-the-garden-and-the-kitchen (opened 2026-10-23)
