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A Guide to Growing Squash: Tips for a Bountiful Harvest

Updated: Feb 7, 2023


Cucurbita are vegetables including squash, pumpkins and gourds in the Cucurbitaceae family. The original squash species were extremely bitter and only palatable to large land mammals, including mastodons. These large mammals did not have bitter taste receptors like smaller mammals do and had no problem eating them. As these large mammals went extinct during the Holocene, so did the wild, bitter types of squash.

The Native Americans began domesticating wild types of squash over 10,000 years ago, making them more palatable and a major food source for them. After Europeans made contact with the Americas, squash was spread throughout the rest of the world.


Squash plants can grow to be quite large, especially the vining type. Ensure to plan for at least one foot of spacing between each plant and at least three feet in width. Squash plants spaced too close together will compete with each other for nutrients, water and sunlight which can reduce yields.

Depending on the variety, squash plants can take up to 45 days after planting to begin flowering. Each flower has potential to become a fruit given the right conditions. Sunlight, water and nutrients are the three components that will determine how successful your squash plants will be. These are sun loving plants that need at least eight hours of full sun each day to produce fruit. Plants that get shaded out by other plants or planted in a low sunlight environment may have stunted growth with little to no fruit.

Ensure the ground stays moist at all times by either hand watering or using irrigation. Squash plants can easily rot if the ground they are growing in stays soaking wet for too long. If rains are predicted, hold off on watering until they pass and don’t resume watering again until the soil has dried some.

A balanced fertilizer designed for fruiting plants is recommended for squash plants. Simply sprinkle the fertilizer on the soil around the base of the plant at the recommended dose on the package. Apply when you first plant and again when the plants develop flowers. Here are some highly rated fertilizers for squash plants:

Squash fall into two categories, summer squash and winter squash. Summer squash should be planted in the spring after the last sign of frost for a summer harvest. Winter squash should be planted in the summer for a fall or winter harvest, depending on when you plant. Planting times are dependent on your location. You can find the dates to plant your squash by typing in your zip code here.

Types of summer squash (bushing):

Straightneck (Cucurbita pepo var. recticollis)

Crookneck (Cucurbita pepo var. torticollia)

Pattypan (Cucurbita pepo var. clypeata)

Zucchini (Cucurbita pepo var. cylindrica)

Types of Winter squash (vining):

Acorn (Cucurbita pepo var. turbinata)

Pumpkin (Cucurbita pepo var. pepo)

Spaghetti (Cucurbita pepo var. pepo)

Butternut (Cucurbita pepo var. moschata)


Before planting your squash, it is important to amend your soil bed with healthy soils that can provide your squash plants with nutrients throughout the growing season. Either compost, manure or a combination of both should be worked into the soil. If your ground soil is clay-like and not well draining, make sure to break it up with a hand tiller or shovel before adding the amendments.

Planting squash transplants

Step 1: Dig a hole deep enough to fit the root ball of the plant in.

Step 2: Gently fill in the hole around the roots and cover the top of the roots with surrounding soil. Gently pack the soil around the base of the plant for support.

Step 3: Top dress the soil around the base of the plant with a granular fertilizer.

Step 4: Lightly cover with fertilizer with surrounding soil.

Step 5: Give the soil and roots a good soaking with water until the soil is saturated.

Planting squash seeds

Step 1: Dig a 1” deep hole and place the seed in it.

Step 2: Add a layer of soil to bury the seed and gently compact the soil over the seed.

Step 3: Give the soil and roots a good soaking with water until the soil is saturated. It is important to keep the soil moist until the seed germinates.

Step 4: Once the plant has germinated and has two sets of leaves, top dress the soil around the base of the plant with fertilizer and cover with a layer of soil.

Three Sisters Planting

The three sisters' companion planting technique was started by the Native Americans with their three most important food crops: Corn, beans and squash. When grown together, these three crops benefit from each other by creating the perfect growing environment for each. The tall corn stalks allow the beans to climb up them and off the ground where the squash grow. The beans fix nitrogen in the soil, making it available for both the corn and squash and the squash grow along the ground to help it retain moisture and prevent weeds from growing.


Squash plants that produce a lot of fruit should be harvested as soon as they ripen to encourage the plant to produce more fruit. Before harvesting, ensure you are wearing long sleeves and gloves because the stems and leaves are spiny and can cause skin irritation.

Summer squash can be harvested early when the fruits are still small because they are flavorful at a young age, but the general rule is to harvest when the fruit is about 5” long. Winter squash takes a few weeks longer to ripen and should be harvested when the rind is stiff and the fruit is hollow sounding when tapped. Winter squash should be harvested before frosts are predicted to save the fruits from freezing. If both summer and winter squash are kept on the plant for too long, the fruit will lose its flavor and develop a corky consistency.

Squash flowers are edible and can be harvested before they are able to produce fruits. If you have high yielding plants and want to reduce the number of fruits or you simply enjoy eating the flowers, simply prune off the flowers before they have a chance to set fruit.


Although squash plants are low maintenance and easy to grow, they aren’t immune from ailments. Two of the most common diseases squash plants suffer from are powdery mildew and bacterial wilt.

Powdery mildew presents itself as a thin, white powdery substance on the surface of the leaves. This disease can spread quickly throughout your plants, especially if they are placed close together. It is most prevalent during warm, humid times of year. Avoid top watering your squash plants to keep the leaves dry and prune off some of the larger, mature leaves for better airflow. To treat powdery mildew, spray a copper fungicide or horticultural oil on the entirety of the plant.

Bacterial wilt is a disease spread by cucumber beetles when they feed on the plant. Signs of infection are the leaves beginning to wilt and eventually the entire plant will wilt and die. Once a squash plant is infected by bacterial wilt, it is not likely the plant will survive and it should be removed and discarded.

Other pests of squash plants are squash bugs and squash vine borers. Squash bugs suck the sap out of the leaves, leaving brown spots. Younger plants are most susceptible to squash bugs and can die if there is a large infestation that can completely defoliate a plant.

Squash vine borers bore holes into the stems of squash plants. Typically, the first signs of a damaged plant by these holes are wilting plants. If your plants look wilted and don’t bounce back after being watered or in the early morning when temperatures are cooler, look for holes in the stems.

Treatment for cucumber beetles, squash bugs and squash vine borers is an insecticidal soap. Spray at the first sign of these insects either feeding on your plants or seen flying in the area of your plants. If there is a large infestation of any of these insects, it is best to avoid planting squash for a couple of years to deter the adults from coming back. The larvae in the soil will eventually die off if they don’t have squash or cucumber plants to feed on.

If you have any more questions about how to grow squash, we will be happy to assist you in a virtual telehealth appointment with one of our Plant Specialists. Please click on one of the options below to book an appointment.


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