key growing information

Growing Butternut Squash

How to grow butternut squash: transplants or direct sowing, spacing by vine length and fruit size, pest and disease prevention, curing, storage and seeding rates.

By Hensley’s Seed Co. September 3, 2026

Butternut Winter Squash - Key Growing Information

Butternut winter squash fruits; this variety is 'Waldo,' an intermediate variety.

SCIENTIFIC NAME:

Cucurbita moschata

CULTURE:

Rich soil that drains freely, with a pH in the 6.0–6.8 range, gives the best results. Plastic mulch plus lightweight row covers (AG-19 weight) help young plants get going and keep insects off seedlings. Take the covers off when flowering starts so bees can reach the blossoms; misshapen or aborted fruit is often a sign that pollination fell short.

TRANSPLANTING:

About 3 weeks before planting out, sow 2–3 seeds in each 2" pot or cell of a plug flat . Snip off the extras with scissors so one seedling remains per cell. Spend 4–7 days hardening the plants off, then set them out after the last frost at the spacing listed for your variety. Squash roots resent disturbance, so move the seedlings gently.

DIRECT SEEDING:

Plant seeds 1/2–1" deep, two at each planting spot, using the spacing that fits the variety's vine length. Once the seedlings are growing well, remove the weaker one at each spot.

PLANT SPACING:

Between rows, allow about 6' for bush and short-vine types and about 12' for long-vine types. In-row spacing depends on both fruit size and vine length: roughly 18–24" for small-fruited bush or short-vine types, 24–36" for medium fruit and vines, and 36–48" for large fruit or long vines. Grown at about 6 sq. ft. per plant, Butterscotch PMR yields small, single-serving fruit of about 1 lb.

DISEASES:

Powdery mildew, downy mildew, bacterial wilt and Phytophthora are the main squash-family diseases. Good drainage, open airflow, controlling insects and rotating crops prevent most problems. For specific treatment options, contact your county Cooperative Extension office.

INSECT PESTS:

Expect cucumber beetles, squash bugs and squash vine borers. Floating row cover shields young plants. Crush clusters of squash bug eggs on leaf undersides by hand. If a borer gets in, slit the stem to remove it and mound soil over the damaged section. Mowing field edges, clearing crop debris in fall and turning the soil in spring to bury overwintering pupae all cut down on pests. Butternut types (C. moschata) are less prone to vine borer damage than other squash. Pyrethrin sprays can help somewhat.

HARVEST:

Fruit typically matures 50–55 days after it sets; bring it in before a hard frost. Cut the stem rather than pulling, and handle fruit gently. Cure it in the sun for 5–7 days, or indoors at 80–85°F/27–29°C and 80–85% relative humidity with plenty of air movement.

STORAGE:

Keep cured squash at 50–55°F/10–13°C and 50–75% relative humidity with good airflow. Temperatures below 50°F/10°C, especially repeatedly, can cause chilling injury. Storage life and peak eating quality differ by squash type; our Winter Squash Curing & Storage Chart gives the details.

DAYS TO MATURITY:

Counted from direct sowing; for transplants, take off roughly 14 days.

AVG. DIRECT SEEDING RATES:

(Based on 2 seeds per foot in rows 6' apart.) About 1 oz per 155', 1 lb per 2,500', or 3 lb per acre.

SEED SPECS:

Varies by variety; see each product page.

PACKET:

30 seeds per packet.