Growing Squash Guide – Summer Squash and Winter Squash

Growing squash is an exciting journey. Unlike root crops that grow underground, here you can watch the growing squash slowly emerge and swell. They are also pleasingly easy to grow. This guide will take you through everything you need to know about growing squash.

Growing squash in the garden is a fascinating journey. The endless choices provided by the many available varieties and cultivars means that you can cultivate a range of different colored and flavored fruit. 

Summer Squash and Winter Squash

Before we discuss growing squash in the garden we need to look at the different varieties. These can be split into two categories- winter squash and summer squash.

Winter squash is harvested in one go at the end of the growing season. These include winter squash cultivars such as butternut squash, pumpkins and spaghetti squash. The skin of winter squash is inedible. Winter squash keeps for longer than summer squash – some cultivars may even last all winter.

Crown Prince is a popular winter squash that has blue skin. Its flesh is orange with a sweet, nutty flavor. It also stores well through the winter. Cobnut is a butternut winter squash which is early to ripen. This winter squash produces large fruits that are ideal for soup or roasting.

Summer squash can be harvested throughout the summer months. These include summer squash cultivars such as patty pan squashes or zucchini. Easy to grow and pleasingly prolific, each summer variety produces a heavy crop of fruit.

Many summer squash varieties are best harvested when they are slightly immature and tender. The skin of this summer squash variety is edible. Summer squash is best used fresh as summer squash doesn’t keep for very long.

Unlike winter squash varieties that can be stored for a prolonged period, summer squash, such as zucchini are best used fresh. Both summer squash and winter squash are pleasingly easy to grow, requiring many of the same conditions in order to fruit. 

Sunburst is a bright, yellow variety with a nutty flavor. Can be grown like a courgette. Jemmer AGM is a reliable yielding hybrid. It produces round, light yellow fruit that is easy to pick. Clarion AGM is another high yielding variety. Its mottled green fruit and cylindrical in shape and ideal for stuffing.

Whether you are growing winter squash or summer squash you will notice that squash is either bushy or trailing. Trailing plants spread over the garden. They can also be trained to grow along trellising. As the stems spread they lay down extra roots. This means the squash can harvest more moisture and nutrients. This leads to the squash producing larger fruit.

Growing Squash From Seed

Growing squash from seed is an easy process.

Sow seeds individually in small containers filled with good quality, fresh compost. Seeds can be sown from mid- March until the middle of June. Cover the seeds and water.

Squash only germinates in warm environments. You will need to place the containers in a warm position, such as on a windowsill or in a heated propagator. Ideally the temperature will be between 60-68℉. Keep the medium evenly moist. Placing the containers into a tray of water allows you to water the squash from the bottom up.

Germination occurs within 10 days. If the conditions are less than ideal this may take slightly longer. As the young squash seedlings grow keep them well watered.

When the seedlings are about 4 inches tall begin hardening them off. Once your last local frost date has passed these can be transplanted into their final position. The soil should be at least 60ºF before planting summer varieties in the garden.

Before transplanting, work the ground over well.

Transplant into a deeply dug hole that has been filled with ample amounts of homemade compost or well-rotted manure. Scatter a couple of handfuls of fish, blood and bone onto the planting surface before transplanting.

When transplanting growing squash plants disturb the roots as little as possible. Plant squash plant to the same depth as when in its pot.

When you plant squash plant, seeds can be sown in their final growing position or in pots for transplanting later on. Before sowing or planting make sure that the soil is warm and enriched. This will help to encourage the squash plants to germinate and flourish. 

Once planted, mound the soil around the plant’s base in a ring that is at least 17 inches wide. This helps to divert water to the root system of the plant. Water well and cover with a cloche. Covering the plants will help to protect against cool weather or unexpected frosts.

Mulching around the base of the plants also helps to protect roots from cold spells. Mulching is also a useful way of improving soil moisture retention and suppressing weed growth. Using an organic mulch such as homemade compost will also enrich the soil as it breaks down.

Space trailing varieties 5 ft apart. Bush varieties can be spaced about 3ft apart. Check the information for exact spacing on the seed packet before transplanting.

Squash Blossom by Thomas Cizauskas / CC BY-NC-ND 2.0 Growing squash from seeds isn’t difficult, and you can choose exactly how many plants you get with it because many of them will sprout. 

Choosing the Ideal Position for Growing Squash

Squash thrive in full sun positions. They also appreciate warm, sheltered locations. Heavy feeders they do best in rich, fertile soil. It should also drain well. Two weeks before planting, enrich the soil by working in homemade compost or well-rotted manure. Organic fertilizer can also be worked into the soil at this stage.

Growing Squash in Containers

Remember, growing squash requires a lot of room. If you can’t grow the squash in the open ground try to grow them in a large half barrel such as a re-purposed rain barrel.

Smaller summer varieties can be grown in containers that are at least 18 inches wide. The larger the container you can use the better. A large container will require less frequent watering.

Your chosen container for squash should be clean and have drainage holes in the bottom. Fill with good general purpose compost and plant as above. Mulch the top of the container to further benefit the plant and help reduce moisture loss.

Growing squash can also be done in grow bags. Plant one squash per bag. As the bags are shallower than containers you will need to water far more frequently.

How to Care for Growing Squash

Once transplanted you need to ensure that the soil surrounding your plants is constantly moist. Water regularly so that it doesn’t dry out. In addition plants will benefit from one deep watering once a week. This helps to encourage growth as well as helping the fruit to swell.

Drought, or dry soil, can stress plants causing their fruit to drop or fail. A soil moisture gauge will help you to accurately monitor your soil, so you will know exactly when to water.

If you are worried about the amount of water you are using why not try harvesting rainwater. The harvested rainwater can then be reused to keep your plants healthy and hydrated.

Mulching the plants with organic matter such as homemade compost helps to keep the soil moist. As the mulch breaks down it adds nutrients, further boosting the growing squash.

Fertilizer

An application of fertilizer can be applied as a side dressing when the first flowers appear.

Fertilize regularly during the harvest period to encourage more growth and fruit production. A high potash liquid fertilizer helps to encourage the fruit to swell. While commercial fertilizers are available, you can easily make an effective, organic plant feed at home.

Support

As the plants spread, peg the stems down at regular intervals. This helps to prevent their spread from completely taking over a space.

Lift larger fruit such as pumpkins onto a tile, seed tray or other suitable hard surface. This helps to prevent them from rotting as they develop.

Raise fruit slightly off the floor by sitting it on a hard surface. This helps to prevent the fruit from pests. It also means that the fruit isn’t contacting damp soil, which can cause fruit to blemish or rot. 

Pruning and Weeding

Remove any yellow leaves. This helps to keep the plant healthy and prevent disease from forming.

If you want fewer but larger fruit, cut the stems off when they reach about 2ft. This limits the number of fruit the plant produces. However any fruit produced will be significantly larger than heavier fruiting plants.

Remove any leaves that cover the fruit. This helps to expose the fruit to as much light as possible.

You may need to weed around the plants when they are young. However squash is a fast growing fruit. This means that they will quickly smother the majority of weeds.

Common Growing Squash Problems

Good growing practices such as regular watering and correct spacing will help to prevent most problems. However there are some issues you should be aware of.

Bacterial wilt and powdery mildew are two of the most common problems. These are particularly common in hot or humid weather. Organic fungicides, as well as home made treatments, can be used to treat problems. Powdery mildew can also be a sign that the plants are not receiving enough water.

Squash vine borers and squash bugs can cause leaves to wilt and die. Cucumber beetles can also target the foliage of plants. Regularly check the foliage of your plants, picking off any visible pests. Larger infestations can be washed away with a blast from a hosepipe.

Regularly check plants and fruit for signs of disease or infestation. Spotting the signs early means that you can cure the problem quickly before the problem worsens and affects the health of your entire crop. 

Slugs and snails can target young plants. There are a number of chemical and organic controls available. Alternatively, homemade solutions such as surrounding the plants with coffee grounds are just as reliable.

Blossom End Rot may cause flowers to turn black and rot. This is an indication that the soil moisture is uneven. It can also be a sign that it is lacking in calcium. Water deeply and mulching well will help to correct this issue.

Companion Planting

Companion planting is the useful process of growing mutually beneficial plants together. Growing summer squash alongside corn and beans is a popular combination. In Native American gardens this combination is commonly planted.

Nasturirums and marigolds are both useful trap crops. These deter aphids and other pests from your plants. Meanwhile herbs like peppermint, parsley, oregano and dill also help to ward pests from squashes. Flowering herbs such as borage will attract pollinators such as honeybees to your plants. This helps to increase your yield.

Planting trap plants such as nasturtiums alongside your crops will help to protect your plants from pest infestations. They will also add color to a space, attracting pollinators and helping to increase your yield.n 

Peas and radish crops also do well alongside winter varieties.

Avoid planting potatoes close to your crops. Both plants are heavy feeders and can stunt each others growth. Pumpkins should not be planted near summer varieties such as zucchini. This can lead to cross pollination and poor fruit.

How to Harvest

Harvest summer varieties while still tender. When harvesting check the growing squash plants every day. During this period the plants are quick to grow and produce more fruit. Frequent harvesting will encourage more fruit production. Winter varieties should only be picked when they are fully matured.

Overly ripe or old fruit will become hard and lose its flavor. They also become overly seedy.

Harvest your fruit before the first frost.

Harvest the fruit by cutting the stalk and gently lifting the fruit away from the plant. Cut the stalk as far away from the fruit as possible.

Summer varieties can be kept in cool, moist areas for up to two weeks. They can also be canned or frozen. An excess of fruit can be cured. Cure the fruit by allowing it to sit in the sun, or on a bright windowsill for up to five days. This will allow you to store the fruit in a cool, dark place for up to three months.

Winter fruit can be stored in cool dry positions for up to 6 months.

Bright, flavorsome and coming in a range of varieties growing winter and summer squash is a fascinating journey. It is also a satisfyingly simple crop to cultivate. Your efforts are rewarded with lots of large, tasty fruit.

How to Keep Winter Squash

Some square varieties can keep for months if you have them in good storage conditions. You have to keep the rind of this full sun vegetable from injury when you store it because injuries to the rind encourage infection and pests. For eating now, you’ll harvest the squash when they reach whatever size you want. For storing them, you’ll need mature fruit. 

Seeing dead vines can be a good indication of ripeness, or you could try to twist the squash off the vine. If it happens to come easily, it’s usually ripe. You can also gauge the ripeness by pushing your fingernail into the rind. If the rind is very hard and difficult to get your nail into, it’s ready. Cut it off with purners while leaving a three-inch stem for pumpkins and a one-inch stem for winter squash. The stem can help prevent rot when you store your winter squash. 

Squashes by Ruth Hartnup / CC BY 2.0 Keeping squash can be a process if you’re not sure what you’re doing, but you can easily get a high yield that lasts for weeks.

Hardening off Squash

Once you finish harvesting your squash, it’s time to harden them off. You’ll do this by rinsing off the dirt and laying them in a single layer. This prevents you from accidentally damaging the rind. This is important because you have to cure the rind. The hardening off process will help to toughen up the skin and create a barrier against mold, moisture, bacteria, and insects that could break down the fruit much more quickly. 

Humidity and high temperatures are two things you need to harden the rind. Cure your squash for 10 days in an area where the temperature stays at least 80°F with 80% humidity. You don’t need to harden off acorn squash because they’ll lose their quality. Occasionally turn your fruits to expose them to air. 

Why You Should Cure Squash

When you harvest your winter squash, the mature fruit has a lot of excess water. Curing the squash will allow a bit of the water to exit, and getting rid of this water will: 

• Reduce the chances of rot 
• Concentrates the natural sugar content to make the squash taste sweeter
• Slows the squash’s respiration rate that enhances the long-term storage 

Once you harvest your winter squash, it’ll keep respiration or breathing. When you cure it, the skin will get harder and form a protective layer over the flesh. When the skin hardens, this slows the respiration rate, and this improves your fruit-keeping qualities. Harder skin will also resist rotting much better. 

Squash Types that Cure Nicely

You’ll want to cure a few different types of winter squash, including Buttercup, Blue Hubbard, Spaghetti, and Butternut. Don’t devote time or space to curing Acorn squash because it reduces the quality and storage life of it. 

How Long Cured Squash Keeps

How you pick and handle your squash will directly impact how well they keep when you store them. The following tips will help ensure your squash cures properly and lasts for a decent amount of time: 

• Remove any blossom bits that are clinging to the bottom of your squash 
• Cure fruit that is free of blemishes. If the skin is bruised or broken, it won’t cure well 
• Keep your squash dry and avoid handling or harvesting wet fruit 
• Use pruners or scissors to cut your squash from the vine. Pulling the squash can break or dislodge the stem, and this creates a big wound that is very likely to rot. 
• Frost shortens your squash’s storage life. A light frost can sweeten some types of winter squash, but it reduces the storage life. Harvest your squash the night before temperatures drop below 40°F. 
• Keep two or three-inch stems on your squash. If the stems get loose or break off, it’ll impact how well your fruit stores. Use any squash with broken stems first without storing it. 

Put your squash in a dry, cool spot to store it. For most winter squash varieties, you’ll store it between 50 and 55°F with a relative humidity level of 60% to 70%. Acorn squash is one one exception to this as you want to keep it at temperatures below 55°F. 

Storing your other types of winter squash at higher temperatures can make it get stringy. Avoid putting it in an area with higher humidity as this can encourage rot. Storage time will vary, but a general guideline is: 

• Acorn – Four weeks

• Blue Hubbard – Six to seven  months

• Buttercup – Thirteen weeks 

• Butternut – Six weeks

• Spaghetti – Four to five weeks

How to Store Summer Squash

• To store summer squash, you’ll want to gently wipe the fruit clean using a damp cloth. Put it in a perforated plastic bag to help maintain the humidity levels and stick it in your vegetable crisper drawer in the refrigerator. 
• Don’t store your summer squash at temperatures that reach below 50°F. The fruit is very prone to chilling injuries when temperatures fall below this point. Chilling injuries show symptoms like water loss, surface pitting, decay, and yellowing. 
• You can freeze zucchini for soup and bread by peeling it and slicing or cubing it. Blach the zucchini by putting it in a wire basket and plugging it into a large kettle of boiling water for three minutes. Cool it by taking it out and putting it in a basket of ice water for another three minutes. Drain the water away and pack it into freezer containers. You’ll boil it for three to five minutes to revive it until it’s fork tender. 

Tips to Plant, Grow, and Store Squash

Just like other crops that grow on vines, squash likes heat. However, it’s slightly hardier than cucumbers or melons.  Squash plants do need full sun, sufficient moisture, and fertile soil to grow well. It’s also recommended to mix in a well-composted material into the soil when you plant them. The soil should also be very fertile and drain well each time you water it. You can add both compost and decomposed manure to inject nutrients into the soil. 

You can sow your squash directly into the garden, or you can easily start it inside. Winter and summer squash commonly get planted in hills that are around an inch deep. Sow your seeds once any frost danger is gone and the soil starts to warm up. You’ll need only four or five seeds per hill, and you’ll thin them down to two or three plants per hill once your seedlings develop their leaves. 

Rows and hills of summer squash should be between three and four feet, and winter squash should get spaced between four and five feet apart to allow them to spread. Between rows, you want to leave five to seven feet with the hills around three feet apart. 

You can start your squash indoors three to four weeks before you plant them. Start your seeds using peat pots, and be very careful not to damage the roots when you transplant them. You can put three or four seeds in a pot and thin them out to two plants later on. Before you plant them, make sure you take steps to harden off the plant to reduce the chances of shock, and wait until the frost recedes. You should also mulch your new plants generously to help reduce weeds and maintain moisture. 

Growing squash is one of the easiest fruits to begin with. An almost instantly rewarding plant, children and adults alike can enjoy watching the daily progress of the plant. Pleasingly squash comes in a range of varieties, meaning that there is something suitable for most people and situations. This versatility has helped to make it a popular member of the vegetable and container garden.