How to Grow Warty Hubbard Squash

Seeds germinate with a single taproot emerging within 7-10 days at soil temperatures above 70°F (21°C). Cotyledons emerge and unfold.

Keep soil consistently moist but not waterlogged. Maintain soil temperature of 70-85°F (21-29°C) for best germination. Plant directly in garden after last frost date.

Plant develops 2-4 true leaves and establishes a stronger root system. Vines begin trailing or can be trellised. Leaves are large and deeply lobed.

Thin seedlings to 1 per hill or space properly. Begin regular watering as plants establish. Mulch around plants to retain moisture and suppress weeds. Provide stakes or trellising if desired.

Vigorous vining growth with large leaves covering substantial area. Plant produces numerous runners that can extend 8-12 feet or more. Male and female flowers begin appearing.

Water deeply and consistently (1-2 inches per week). Apply balanced fertilizer every 3-4 weeks or use side-dressing of compost. Manage vines to prevent excessive overcrowding; prune if needed for air circulation.

Large yellow flowers appear, with female flowers (those with small round bases) developing into small squashes. Fruit begins swelling rapidly once flowers are pollinated.

Ensure adequate pollinator access; attract bees with flowering companion plants. Reduce nitrogen fertilizer to avoid excessive leaf growth at expense of fruit. Continue consistent watering.

Squashes grow to 8-12 inches in diameter, developing the characteristic warty, blue-gray skin. Skin hardens and deepens in color as maturation completes. Stem begins to cork over.

Reduce watering frequency to concentrate sugars and harden skin. Allow vines to mature fully without harvesting prematurely. Remove any diseased or damaged fruit. Stop watering 1-2 weeks before harvest.