When to plant winter squash by city
Start winter squash indoors 3–4 weeks before your last frost, plant them out 1–3 weeks after your last frost, or sow seed outdoors 1–3 weeks after your last frost, once the soil is at least 65°F. Here is what that means for 2027 in cities across the US, using each city’s average frost dates and the date its normal daily temperature reaches 65°F, so cool-spring places like Seattle wait for real warmth (NOAA 1991–2020). Pick the city with the climate most like yours, or enter your ZIP code above.
| City | Last frost | Start indoors | Plant out | Sow outdoors |
|---|---|---|---|---|
| Seattle, WA (9a) | Mar 13 | May 26 – Jun 2 | Jun 30 – Jul 14 | Jun 30 – Jul 14 |
| Portland, OR (8b) | Feb 25 | May 21–28 | Jun 25 – Jul 9 | Jun 25 – Jul 9 |
| Sacramento, CA (9b) | Jan 12 | Mar 28 – Apr 4 | May 2–16 | May 2–16 |
| Phoenix, AZ (10a) | Jan 5 | Feb 2–9 | Mar 9–23 | Mar 9–23 |
| Salt Lake City, UT (7b) | Mar 31 | Apr 19–26 | May 24 – Jun 7 | May 24 – Jun 7 |
| Denver, CO (6a) | Apr 30 | Apr 25 – May 2 | May 30 – Jun 13 | May 30 – Jun 13 |
| Dallas, TX (8b) | Mar 2 | Mar 2–9 | Apr 6–20 | Apr 6–20 |
| Minneapolis, MN (5a) | Apr 23 | Apr 29 – May 6 | Jun 3–17 | Jun 3–17 |
| Kansas City, MO (6b) | Apr 4 | Apr 5–12 | May 10–24 | May 10–24 |
| Chicago, IL (6b) | Apr 10 | May 2–9 | Jun 6–20 | Jun 6–20 |
| Columbus, OH (6b) | Apr 20 | Apr 18–25 | May 23 – Jun 6 | May 23 – Jun 6 |
| Nashville, TN (7b) | Apr 1 | Mar 31 – Apr 7 | May 5–19 | May 5–19 |
| Atlanta, GA (8a) | Mar 24 | Mar 23–30 | Apr 27 – May 11 | Apr 27 – May 11 |
| Raleigh, NC (8a) | Mar 28 | Mar 27 – Apr 3 | May 1–15 | May 1–15 |
| Philadelphia, PA (7b) | Mar 30 | Apr 7–14 | May 12–26 | May 12–26 |
| Boston, MA (7a) | Apr 4 | May 1–8 | Jun 5–19 | Jun 5–19 |
In frost-free parts of Florida, southern California and the Gulf Coast, timing is about heat instead: plant winter squash in late winter or early spring and again in late summer.
Don’t go by the calendar alone. Winter squash planted into cold soil sit still for weeks; wait until the soil 4 inches down is at least 65°F and nights stay above 50°F.
Winter squash spacing
In a square-foot bed, plant one plant per 9 square feet (a 3 × 3 ft block). In traditional rows, space plants about 48 inches apart with 72 inches between rows.
Butternut and acorn sprawl 10 feet. Train vines out of the bed.
How to grow winter squash
Butternut, acorn, delicata and other winter squash need a long, warm season and lots of room; vines can run 10 feet. In return they give a harvest that keeps for months, worth the space for gardeners who like to store food.
Sun and soil
Full sun and rich, well-drained soil, pH about 6.0–6.8. Plan on 1–2 inches of water a week while vines grow and fruit sizes.
Planting
- Sow 1 inch deep 1–3 weeks after the last frost, once soil is 65°F, 2–3 seeds per hill thinned to one or two. Or transplant 3–4-week-old seedlings without disturbing roots.
- Space hills 48 inches apart in rows 72 inches apart.
- Count back the days to maturity from your first fall frost so fruit has time to ripen.
Care
- Train vines out of the bed onto a path, or grow small acorn and delicata types on a sturdy trellis.
- Side-dress with nitrogen when vines start to run, then stop.
- Ease off watering as fruit matures, and set fruit on a board or straw to keep it off wet soil.
Harvest
Harvest when a thumbnail will not dent the rind, color is deep and even, and the stem is turning corky. Cut with a few inches of stem before a hard frost. Cure butternut types at 80–85°F for about 10 days (acorn needs no curing), then store at 50–55°F.
Common problems
- Squash bugs: Hand-pick bugs, crush egg clusters, trap adults under boards, and clear vines after harvest.
- Squash vine borer: Butternut and other C. moschata types have solid stems that borers rarely damage. Row cover other kinds until flowering.
- Powdery mildew: Common by late summer. Plant resistant varieties and space vines; late infections mainly reduce sweetness.
Varieties to try
- 'Waltham Butternut' — reliable, stores well
- 'Table Ace' — compact acorn
- 'Cornell's Bush Delicata' — semi-bush, sweet striped fruit
- 'Pink Banana' — huge fruit for long seasons
Crop rotation
Winter squash belong to the squash family (Cucurbitaceae). Heavy feeders. Cucumber beetles and powdery mildew carry over between years. Relatives that count as the same family for rotation: cucumber, zucchini, yellow squash, pumpkin, cantaloupe, watermelon.
Frequently asked questions
When should I plant winter squash?
What grows well with winter squash?
How far apart should I plant winter squash?
How long do winter squash take to grow?
Can winter squash handle frost?
Sources
- Frost dates: NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020.
- Hardiness zones: 2023 USDA Plant Hardiness Zone Map, USDA-ARS and PRISM Climate Group, Oregon State University.
- Planting windows and spacing: Vegetable Planting Guide (GardenNotes #720), Colorado State University Extension, and other land-grant extension guides.
- Trap cropping: a review of the state of the art, Sarkar et al., 2018 (open-access review)
- Food Yields and Nutrient Analyses of the Three Sisters, Jane Mt. Pleasant, Ethnobiology Letters 7(1), 2016
- Gardening with Companion Plants (EM128E), Linda Chalker-Scott, Washington State University Extension, 2023
- Pumpkins & Winter Squash — Clemson Cooperative Extension (HGIC)
- Summer and Winter Squash in the Garden — Utah State University Extension