Vegetable / Warm season
Butternut Squash
Also called butternut pumpkin
The squash vine borers mostly skip, and it keeps for months
Plant out byMay 18zone 6
- Family
- Gourd (Cucurbitaceae)
- Sun
- Full sun (6+ h)
- Difficulty
- Easy
- Days to harvest
- 80-110 days
- Spacing
- 48 in apart, rows 72 in
- Pot size
- Beds only
- Frost
- Tender
- Start
- Either
- Water
When to plant
Showing .
Averages for a typical garden in the region. Your local frost dates may differ by 2-3 weeks, check a local source.Too late this year (try fall)
In zone 6, start seeds indoors Mar 23 to Apr 6; plant out Apr 27 to May 18. Average last frost Apr 20, first fall frost Oct 20.
Units
Butternut is the squash for anyone who watched a zucchini collapse in July. It belongs to a different species, Cucurbita moschata, with solid, tough stems that squash vine borers mostly leave alone. Zucchini and most pumpkins have hollow stems the larvae can tunnel through. Clemson's extension calls butternut close to immune. Mostly is the key word, so still glance at the base of the stem now and then.
Here is the catch: space and time. A standard vine wanders well past the edge of a bed, and each plant wants 50 square feet or more. Squash bugs and cucumber beetles still show up. The fruit takes roughly 80 to 110 days. You sow after your last frost, wait all summer, and pick on a dry day. By then the vine has died back and a fingernail cannot dent the rind. Green stripes on the skin mean it needs more time.
Pots are a stretch. Bush types like 'Butterbush' stay shorter, but most growers keep butternut in the ground and train the vine along a fence or the path edge. The payoff comes later. Fruit kept in a cool, dry room near 50 degrees F often lasts two to three months, sometimes longer. I like having one on the counter in January that came from the yard. Roasted cubes are the one squash dish my kids eat without a debate.
Things to consider
- Fruit only sets after bees visit the female flowers. Skip daytime insecticide sprays during bloom, or the pollinators take the hit. If fruit still will not set, move pollen from a male flower to a female one with a soft brush early in the day.
- Cut, do not twist, and harvest before a hard frost. Fruit with a broken stem or frost damage will rot in storage instead of keeping. Use pruners or a sharp knife, and never lift the fruit by its stem.
- Keep stored squash away from apples and pears. Ripening fruit gives off ethylene, and squash shelf life drops when they share a shelf. Store them in a single layer with air around each one, and check every couple of weeks for soft spots.
Good neighbours
Keep apart
Pests to watch for
Squash bugsCucumber beetlesAphids
Questions about growing butternut squash
Does butternut squash need curing?
Illinois Extension suggests curing most winter squash, butternut included, for 10 to 20 days at about 70 degrees F. A warm room toughens the skin and lets small scratches seal. Whatever you choose, store only fruit with an intact stem and unbroken skin.
Why are my butternuts still green in September?
Butternut needs a long frost-free stretch, so late sowing or a cool summer can leave fruit short of time. Pick what you have before frost. Immature squash is fine to cook soon but will not store as long. Next year, sow as soon as the soil warms, or start seeds indoors 2 to 4 weeks ahead in pots you can plant whole.
Can I grow butternut on a trellis?
A sturdy trellis or cattle panel works, since the fruit is mid-sized. Tie the vines in as they grow and slip a cloth sling under heavier squash. It saves ground but needs a strong frame. Put it on the north side so it does not shade the rest of the bed.
Save this crop
Pin it to a garden board so it is there when planting time comes round.
Similar crops
Sources
General guidance for home gardens. Frost dates are averages for a zone or region; check a local source (in the US your county extension office) for local timing.