Waltham Butternut

Butternut Squash

Zone 6b Save Garden

Botanical illustration of Waltham Butternut

🌱 90d to harvest Vine

Honey-sweet, deeply aromatic flesh with a rich, silky, spoon-tender texture—Waltham Butternut delivers classic butternut flavor i…

Crop Dates

Milestone	Date
Start Indoors	Apr 25th
Last Frost	Apr 25th
Transplant / Sow Outdoors	May 9th
Harvest Begins	Aug 7th
Harvest Ends	Oct 16th

Crop Details

Trait	Value
Days to Maturity	90
Sun Requirements	Full Sun
Growth Habit	Vine
Support Needed	Trellis
Planting Depth	Normal
Germination Temp (°F)	85
Min Soil Temp (°F)	65
Min Night Temp (°F)	55
Harden Off (days)	12

Recommended Companions

Autumn Beauty Corn

Salmon Baby Nasturtium

Frequently Asked Questions

What pest or disease is most likely on Cucurbita moschata (Waltham Butternut) and how do I treat it?

Watch for squash vine borer and cucurbit downy mildew. For vine borer, inspect stems near the soil line weekly, then slit the stem and cover the injured area with moist soil after removing frass, which often allows new roots to form; use row cover early until vines are established. For downy mildew, improve airflow by spacing plants and removing heavily infected leaves, then apply a labeled fungicide early at the first signs of yellow angular spots on upper leaves.

How often should I water Waltham Butternut during the main growing phase to avoid fruit issues?

During active vine growth and fruit sizing, keep soil consistently moist but never waterlogged—about 1 inch (2–2.5 cm) per week total, adjusted for heat and rainfall. Water deeply at the base in the morning so leaves stay dry, and let the top 1–2 inches (2.5–5 cm) of soil dry slightly between waterings to reduce mildew pressure. Cut back watering once fruits have fully colored and the rind is hardening to help prevent watery, poorly curing squash.

How can I tell when Waltham Butternut (Cucurbita moschata) is ready to harvest?

Harvest at about 90 days when the skin is fully tan and the rind is hard enough that you can’t easily puncture it with a fingernail. The stem should be starting to dry and turn corky, and the squash should sound dense when tapped. Cut with a sharp tool leaving 1–2 inches (2.5–5 cm) of stem to improve curing and storage life.

Honey-sweet, deeply aromatic flesh with a rich, silky, spoon-tender texture—Waltham Butternut delivers classic butternut flavor in a dependable 90-day season. The elongated, tan-gold fruits are easy to handle and roast beautifully, with a naturally smooth consistency that also shines in creamy soups, hearty purees, and savory sauces. Grow it for a long-lasting harvest that turns your garden into a steady supply of comforting, autumn-ready squash.

Sowing Tips

Transplant Conditions

Wait until soil reaches 65°F and nights stay above 55°F before moving outdoors. Harden off for 12 days first.

Direct Sow Preferred

Sensitive roots — does not transplant well. If starting indoors, use biodegradable pots and disturb roots as little as possible when moving outdoors.

Expert Note

Start seeds or transplants only once nights are consistently warm, and give plants lots of space because Waltham Butternut is a heavy vine grower with long-season storage fruit.