How to Grow and Care for Crookneck Squash (Yellow Squash)

Enjoy delicious, fast-growing crookneck squash all summer

Crookneck squash yellow vegetable growing at base of long thick stems

The Spruce / Adrienne Legault

Crookneck squash, named for the slight curves in their narrow necks, are easy to grow. This cultivar of Cucurbita pepo, a type of summer squash, is also called yellow squash.

These warm-season vegetables grow fast. They have huge leaves that bear small, sticky spines and have a bushy growth habit. Their yellow fruits, which form underneath the leaves, can have smooth or bumpy skins.

For the best taste, pick them when they’re about five to six inches long and tender. The plants are so productive that one or two plants are usually enough to feed a family.

Botanical Name Cucurbita pepo
Common Name Crookneck squash, Summer squash, Yellow squash
Plant Type Vegetable, annual
Mature Size 2 feet tall, 3 to 4 feet wide
Sun Exposure Full sun
Soil Type Loamy, well-drained
Soil pH 5.8 to 6.8
Bloom Time Summer
Flower Color Yellow
Zones 3 - 10 (USDA)
Native Area North America, Central America, South America

Crookneck Squash Plant Care

Crookneck squash are best grown from seeds sowed directly in the garden. They like loose, moist, fertile soil but can grow in almost any type of soil. They need warm temperatures to bear fruits.

These fast-growing plants can spread 3 to 4 feet across with leaves that are 1 to 2 feet wide, so give them plenty of room. Learn about your variety and space your seeds or transplants as directed on the plant tag or label. Thin seedlings as directed.  

Because they’re bushy plants, crookneck squash don’t have to be staked and can grow in large containers or in the ground. However, you might want to put cages around garden plants to keep the leaves from flopping over in bad weather. The fruits usually mature in 45 to 55 days. If you harvest fruits regularly, the plants will bear until frost.

Crookneck squash with long curved yellow vegetable attached to thick stems near buds

The Spruce / Adrienne Legault

Crookneck yellow squash attached to thick plant stems closeup

The Spruce / Adrienne Legault

Crookneck squash growing near base of thick stems and yellow blooms about to open

The Spruce / Adrienne Legault

Light

Crookneck squash need 6 to 8 hours a day of full, bright sun to produce fruit. The plants can be grown indoors in large containers with drainage holes and well-draining potting soil, near a bright, sunny window or under grow lights.

Soil

These plants like a soil pH of 5.8 to 6.8. They also need organically rich soil that drains easily. If you’re growing them in the ground, loosen the soil and remove sticks and other debris. Improve the soil by working in 3 to 4 inches of compost, leaf mulch, or other organic matter.

Crooknecks can be planted in raised beds or containers in good quality, packaged potting soil. You can also make your own container potting soil.

Water

Crookneck squash plants like to stay moist, but not soggy. If rainfall is lacking, water deeply with 1 to 2 inches of water per week. Avoid getting water on the foliage, which makes it vulnerable to diseases and attractive to pests. Water early in the day so any damp foliage can dry out before dark. This also helps the roots absorb the water instead of losing it to evaporation. Plants grown in containers typically need more frequent watering than those in the ground.

Temperature and Humidity

Crookneck squash grow best in air temperatures of about 65 to 75 degrees Fahrenheit. They grow slowly or stop growing in temperatures below 60 degrees F. At temperatures of 85 degrees F. and above, they produce less fruit and grow more slowly. While the plants tolerate high humidity, wet heat can encourage fungal diseases.

Container-grown plants can be moved indoors during periods of extreme heat and humidity, although they still need six or more hours of bright light daily as well as good air circulation and sufficient water and fertilizer.

Fertilizer

For best results, perform a soil test to determine if the garden soil is deficient in any key nutrients. These plants are heavy feeders and need regular fertilizer. Use a balanced formula such as 10-10-10 as directed on the label.  Don’t add extra nitrogen, which encourages foliage to grow at the expense of flowers and fruits.

Crookneck Squash Varieties

  • ‘Early Summer’ is an heirloom crookneck variety with a meaty texture and bright yellow-gold bumpy skin. The plants take about 53 days to mature.
  • ‘Pic-N-Pic’ is a hybrid summer squash that bears heavily. The skins are tender and smooth, and the 8- to 10-inch fruits are ready to harvest in about 50 days. The plants spread 3 to 4 ft. and grow to 30 inches tall. 
  • ‘Sunny Supersett’ squash have sweet, nutty-tasting flesh and glossy, thin, smooth skins. The plants resist mildew and have a few prickly spines. They bear early, in about 40 days and out-yield older varieties.

How to Grow Crookneck Squash From Seed

For a jump start on the gardening season, sow squash seeds indoors in trays or peat pots filled with well-draining potting mix about two weeks before your last frost. Provide them with five to six hours of bright sunlight daily and water them when the mix feels dry to the touch. If you plant more than one seed per pot, when the seedlings have two leaves, thin them to keep only the strongest seedlings. Wait until the weather is reliably warm before transplanting seedlings into the garden.

You can also sow the seeds directly in the garden when the soil temperature is 70 degrees Fahrenheit or higher, or about two weeks after the last frost. Sow seeds in groups of three in slightly raised hills. Cover them with one inch of soil, leaving 18 to 24 inches between the hills and 24 to 36 inches between the rows. Water the seeds well. Thin to the strongest seedling in each group.

Harvesting

Crookneck squash fruits grow at the base of the plants, under the leaves. Harvest fruits often to keep the plants producing until frost.

Most crookneck squash plants have spines on their stems and leaves, so wear gloves to avoid being pricked. Use a knife or garden shears to cut the fruits off the plant when they are five to six inches long, about 45 to 55 days after planting.

To determine if fruit is ready to harvest, gently press them with your thumbnail. If you see an indentation, they’re ready to harvest. Don’t press too hard or you'll break the skin.

Common Pests and Diseases

Crookneck squash are often plagued by squash bugs, cucumber beetles, squash vine borers, snails, and slugs.  Sap-sucking aphids and whiteflies also are common pests.

Diseases include squash blossom blight, cucumber bacterial wilt, and mosaic viruses.

Check your plants often to manage problems before they become serious. Rotate crops in the Cucurbit family, which includes crookneck squash plants, every three years to discourage overwintering pests and fungal disease.