How to Grow Butternut Squash in Hills

Mound your garden soil into hills approximately 6 to 8 inches high and 2 feet across with a garden hoe. Space the hills 4 to 8 feet apart in the garden. The raised soil warms faster and drains easily, preventing issues with cool, wet soil.

Spread a 3- to 4-inch layer of well-rotted mature or compost over the area and work it in with a garden hoe or hand tools. This adds organic matter to the soil, which improves both aeration and drainage while providing slow-release nutrients to the soil. Alternately, an application of one cup bone meal and one cup blood meal per 100 square feet of garden area can be used as organic fertilizer. According to the Colorado State University Extension services, 2 pounds of urea per 1,000 square feet can be used instead, if preferred.

Cover the hill with black plastic and cut large four to six large Xs in the plastic for the plants. This warms the soil, conserves moisture and creates a weed barrier.

Plant the butternut squash seeds in the marked areas, to a depth of 1/2 to 1 inch, after all danger of frost has passed in your area and the soil has warmed to 65 to 70 degrees Fahrenheit. According to the Cornell University Extension, squash will not germinate is cool soil and germinates best at 95 degrees. Alternately, transplant squash seedlings through the Xs cut in the plastic mulch.

Water to saturate the soil to 2 to 3 inches deep and keep the area moist until seedlings emerge in five to 10 days.

Thin the seedlings to two or three per hill when they are 3 to 4 inches tall. Cut the smaller seedlings at the soil level to prevent disturbing the roots of nearby seedlings when thinning.

Water butternut squash once or twice a week or whenever the soil feels dry 1 inch below the surface. Typically, winter squash requires 1 inch of rain each week and might require supplemental watering during dry periods.

Harvest butternut squash by cutting it from the vine, leaving a 1-inch stem, in late summer or fall when the outer skin has dulled and cannot be penetrated with your fingernail. Immature squash have tender skins and appear shiny. Butternut squash will keep for two or three months if stored at 55 degrees with humidity levels between 50 and 70 percent.