How to Grow Spaghetti Squash

If you like growing interesting and unusual crops in your garden, be sure to include a few spaghetti squash vines (Cucurbita pepo). This ordinary-looking variety of winter squash is far from ordinary when cooked, with flesh that separates spontaneously into long, thin yellow lengths that look remarkably like spaghetti when scooped from the rind. Also called gold string melon or vegetable spaghetti, this type of squash is easy to grow but needs lots of sun, even moisture and a long growing season to mature.

Like all squash, spaghetti squash is frost-sensitive and grown as an annual in all parts of the United States. It takes 90 to 100 days from planting time to produce mature squash , so it helps to start seeds indoors if spring tends to be cool where you live. Start seeds indoors in flats or small pots three or four weeks before the expected date of the last spring frost, water soil to keep it moist and, once seedlings emerge, keep them in a bright, sunny window. Plant seedlings outdoors when soil has warmed to 70 degrees Fahrenheit or about two weeks after the last frost.

To speed soil warming, plant in raised beds or rows.

If your area has warm springs, you can direct-seed spaghetti squash in the garden. Before planting seeds or seedlings in the garden, mix about 3 inches of compost into the planting area to increase the soil's organic content. Allow about 4 feet between seedlings to give the vines room to spread or plant in small hills, with two or three seeds or seedlings per hill.

Spaghetti squash plants grow best in full sun and when given even, consistent moisture throughout the growing season, so water plants whenever the soil surface feels dry to the touch. Mound the soil slightly around each plant's base to prevent entry of squash borers, which lay eggs on the plants. Once this is done, add 2 or 3 inches of organic mulch under the plants to conserve soil moisture and keep down weeds that compete for moisture and soil nutrients, but keep mulch back a few inches from the plant's base to discourage fungal growth.

If the garden is small, conserve space by allowing spaghetti squash vines to climb a trellis.

It's also helpful to cover young squash plants with floating row covers in spring. Covers help prevent chilling of the young plants on cool nights and prevent egg-laying by flying insects whose larvae can cause damage later in the season; remove covers before flowering begins because squash production requires pollination by insects. In mid-summer, fertilize plants by adding a granular, 27-3-3 formula into a shallow trench beside the row or encircling each hill; use about 1 cup for each 25 feet of furrow and mix it into the soil, exercising care not to disturb roots.

Each spaghetti squash vine yields four or five fruits, with each one about 10 inches long. The outside of each squash starts out white but gradually changes to yellow as it matures. You'll know the squash is ready to pick when its rind is too hard for your fingernail to dent. Harvested squash usually store without spoiling for several weeks, but it's important to cut each mature squash free with a sharp knife, leaving about 2 inches of stem attached to the fruit-- this helps prevent rotting of the fruit. Clean the knife by wiping it in rubbing alcohol between cuts to prevent spreading plant disease.

Spaghetti squash plants are susceptible to several fungal problems, including downy mildew and powdery mildew, which produce fluffy white growth on leaves, and several types of blight that cause rotting of stems and black, soft areas on developing fruits. Avoid these problems by spacing plants properly and regularly clearing away plant debris. It also helps to water only on sunny mornings when water dries quickly or use a soaker hose or drip irrigation. If you encounter fungal problems, grow squash in a different location each year.

These plants can also attract squash bugs, large, flattened, dark-brown insects that suck plant juices. They are especially damaging to young plants, so hand-pick and destroy these whenever they appear. Other pests such as striped cucumber beetles are also most damaging to young plants. Control these by using floating row covers early in the season and hand-picking them as plants mature.