How to Plant, Grow, and Care for Spaghetti Squash

All squashes are similar in growing habits, and most of the care regimen is nearly identical. However, growing spaghetti squash is a smidgen different in a few ways; the rind is hard but not as hard as some other winter squash varieties, and the color is very distinct on most spaghetti squash varieties when it’s time to harvest. 

These squash vines produce relatively heavy fruit. Growers may want to tie spaghetti squash with a trellis to support their vines and the growing fruit. Even the vines that splay out for eight feet can use a little bit of mulch underneath to help protect the fruit from decay! 

Of course, the most distinct difference in spaghetti squashes is their noodly-textured flesh. This unique flesh is used culinarily as a pasta replacement.

What is a Spaghetti Squash?

Spaghetti squash is a member of the winter squash family. It is also known as vegetable spaghetti and comes in many varieties. It is relatively easy to grow, thriving in gardens or pots.

Native Area

Like most squash, its wild ancestors originated from Central America and Mexico. This particular subspecies, Cucurbita pep ssp. ovifera was first recorded in China in 1850, although how it arrived there and its exact origins are unknown. 

Characteristics

The plants are monoecious with male and female flowers on the same plant. Male flowers have long, thin stems that extend upwards from the vine while female flowers are shorter, with a small round growth underneath the petals.

Varieties

‘Tivoli’ is a dwarf variety that is a great option for gardeners with limited space. ‘Small Wonder’ produces compact fruits, making the perfect single serving a good choice for smaller families or those who may not eat an entire squash in one sitting. There are also striped hybrid varieties such as ‘Stripetti’ and ‘Sugaretti’. 

Planting

You may choose to either direct sow spaghetti squash seeds or transplant out squash seedlings depending on the length of your growing season. To determine the length of your growing season you’ll need to calculate the number of days between your last frost and first frost date. Begin planting a few weeks after the last frost. 

Spaghetti squash is extremely frost-sensitive and can only be grown between these two dates in your zone. Since it needs such a long growing season, taking between 90 and 100 days to fully mature, it can be beneficial to transplant squash seedlings in areas with a shorter season. If your season is long enough, you may direct sow seeds. Alternatively, you can do both! Transplanting seedlings and direct sowing late-season crops at the same time can give a staggered harvest. 

When direct sowing, it’s best to sow seeds in groups of two or three, a few feet apart. Cover seeds with about an inch of soil and keep the soil moist until the spaghetti squash seeds germinate. Once each squash sprout is established and at least a few inches tall, thin the weakest seedling from each group. 

Spaghetti squash can be grown directly in the ground and allowed to sprawl or trained up a trellis. It can also be successfully grown in containers and raised beds and allowed to trail over the sides. ‘Tivoli’, which has short vines and grows about two feet tall and three feet wide, is the perfect choice for a five-gallon container. Be sure you are planting squash in an area of the garden that receives full sun in well-drained soil, and you’ll be rewarded with more than you know what to do with! 

How to Grow

Spaghetti squash is a great addition to your winter squash collection. These squashes are very easy to care for. Below, we’ll discuss how to grow spaghetti squash by providing it with ideal growing conditions. 

Light

Spaghetti squash requires six to eight hours of direct sunlight per day for optimal growth. It can be grown in USDA zones 2-11, however, it does best in zones 5-9 where the length of the growing season is ideal: not too hot and not too cool. 

Water

Spaghetti squash doesn’t do well during extended periods of extreme heat. When combined with a lack of moisture, this spells disaster for your squashes. Water your spaghetti squashes regularly during the heat to keep the soil around the roots cool and protect it from heat damage. Regular deep watering helps support each spaghetti squash leaf and squash fruit. Spaghetti squash requires one to two inches of water per week, equating to a deep watering once per week. Keep the soil moist but not soaked.

Like most squashes, they are particularly susceptible to powdery mildew and downy mildew. For this reason, it is a best practice to water them early in the day at the base to prevent wetting the foliage. It is easiest to place young seedlings along drip irrigation lines to ensure that they receive this deep watering without wetting their leaves. The large leaves may wilt slightly in the heat of the day, but fear not, this is not a sign of underwatering. They will perk back up once the sun sets and the heat of the day has passed. If you witness wilted leaves early in the morning, before it is hot outside, then you may consider increased watering. 

Soil

Grow spaghetti squash in moist, well-drained, nutrient-rich soil for the best results. If you’re struggling with poorly draining soil, then carry out spaghetti squash growing in a container or a raised bed where you can better control the soil mix.

Conversely, if you’re experiencing an issue with the soil draining too quickly and drying out in the garden, then add compost and a layer of mulch to help retain moisture. A fresh layer of compost early in the growing season can provide the soil with all of the organic material that it needs to support this heavy feeder. 

Temperature

Like most plants in the Cucurbita family, spaghetti squash cannot handle even 32°F (0°C). In extreme heat (temperatures above 90°F or 32°C), the blossoms may drop, and fruit may fail to form. If you’re expecting a series of above 90°F days, then it might be best to protect your spaghetti squash plants with shade cloth. This is why late summer planting is not recommended in some areas. 

Fertilizing

Once blossoms appear, then you may consider adding a granular fertilizer. It’s unnecessary to fertilize your squash, but you will see a boost in production if you utilize it at this point. When selecting a fertilizer, be sure to choose one slightly higher in phosphorus rather than nitrogen. High nitrogen fertilizer will cause the plant to focus on foliage growth, which is not what you want at this stage. A fertilizer slightly higher in phosphorus will encourage more blooms, diverting resources to produce more fruit. 

Maintenance

It is not necessary to prune your spaghetti squash vines at all. However, pruning helps keep it compact and focus all of its energy on fewer fruits, rather than more average-sized fruit. Pruning is optional during the growing season, but better at the end of the season. When you’re within 30 days of your average first frost date, prune back additional squash blossoms (they’re edible and delicious fried so don’t throw them away!) This way the vine can focus on ripening the remaining fruits. 

Dwarf varieties are more bush-like and don’t require pruning. A trellis is a great way to utilize the vertical space, making harvesting spaghetti squash easier. This makes them more visible and less likely to be hidden on the ground under large fan-like leaves. A squash trellis can be made from any sturdy material that can either be driven into the ground or tied off to stakes or t-posts. My favorite option for this is to use a cattle panel attached to a t-post on either end. 

As the vines grow, weave them through the lower level of your trellis, and then they will take hold on their own. When growing vertically, keep in mind that the fruits won’t be supported by the ground as they grow. Once the fruits develop, you can cradle them with a t-shirt, old pantyhose, or any similar flexible, but strong fabric. At the end of the season, cut it back at the base and pull the vines from your trellis. If you live in an area with squash vine borers and squash beetles, then you may want to pull up the roots and discard every part to avoid providing them with the perfect environment to overwinter. 

Propagation

Spaghetti squashes can be propagated from cuttings, but it’s not a reliable method and has a very low success rate. The vines don’t readily set roots in the way that tomato vines do. It’s much easier to grow squash from seed or to transplant seedlings. For more information on how to germinate squash seeds, see the Planting section. 

Harvesting

Now that you’ve successfully grown your squash, it’s time to reap the fruits of your labor and harvest spaghetti squash! After you harvest spaghetti squash, then it’s time to consider how to store it. We’ll discuss a few different options below. 

Spaghetti squash season is generally at the end of summer and into early fall. There are visual cues to look for to determine when to pick spaghetti squash. Ripe spaghetti squash will be fully yellow in appearance. The outer rind will begin to harden and the stem will begin to turn from green to brown. Green spaghetti squash is a sign that it is still immature and unripe. Eat this squash when young and immature like summer squash, but it will not fully ripen once removed. It is possible to place them on a sunny window sill to continue to turn yellow, but they will not have the shelf life of a vine-ripened mature squash.

When you harvest spaghetti squash, be sure to use a sharp pair of gardening shears and leave at least two to three inches of the stem attached. This will help extend their shelf-life. It’s important to cure before you store spaghetti squash. Wipe them with a damp cloth or alternatively a solution of one part bleach to ten parts water to help remove any mold and mildew. Place them in a dry, protected area like a garage or shed for a week, and then they are ready to be stored. 

Storage

There are a few different options here depending on how you’d like to use them. Cooked spaghetti squash can be stored in Ziploc bags in the freezer for up to a year. If you plan on using your squash as a pasta alternative, this method works great! Pull your frozen pre-cooked squash to thaw in the refrigerator overnight. Heat your sauce and toss in the squash to heat through. 

A less popular way to eat spaghetti squash, but still delicious, is roasted in cubes. You can freeze raw spaghetti squash flesh cubes, roast them as needed, or toss them directly into soups and stews. Alternatively, properly cured spaghetti squash will last in a cool, dry environment for up to three months. Once the squash has been cut, it will last in the refrigerator for one to two weeks. Pressure-canning, dehydrating and freeze-drying are all options for much longer-term storage. Don’t forget that the seeds can be roasted, like pumpkin seeds, and eaten as well! 

Common Problems

Learning how to grow spaghetti squash and meeting spaghetti squash needs is relatively easy. There are, however, some pests and diseases that can threaten growth and prevent you from harvesting a good crop. 

Growing Problems

Most squash growing problems arise from poor quality soil. If you notice lackluster growth or a failure in bloom formation, consider testing your soil. Make sure the soil is well-draining and not overly moist. Spaghetti squash is also considered a heavy feeder and needs plenty of organic material and/or fertilizer to support its growth. These vegetables will also not tolerate acidic soil. If everything else checks out, then a soil pH bloom test may be necessary to make sure it is within a neutral range. 

Like most members of the cucurbit family, spaghetti squashes have both male and female flowers. The male flower has a long thin base, and the female flower has a tiny spaghetti squash shape at the bottom that will turn into a viable spaghetti squash once it is successfully pollinated. If you notice any shriveling up, then you likely have pollination issues. If the female flowers fail to get pollinated, then they will shrivel up and die rather than produce fruit. Attracting pollinators to your garden with companion plants such as dill, chamomile, nasturtium, and other flowering herbs helps with pollination. When all else fails, you can easily hand pollinate to ensure production by taking a Q-tip and brushing it on the inside of a male flower and then moving it to the inside of a female. 

Pests

Many members of the Cucurbita family have common pests. Among these insect pests, cucumber beetles, squash vine borers (SVB), and squash bugs are the most common. SVB, as their name suggests, bore into the vines where they lay their larvae. This prevents the taking up of water, and it will eventually wilt and die. These pests are found in the eastern United States. Bt spray can be used to destroy vine borers and can even be injected into the stem to kill their larvae. 

Crop rotation can be a good preventative measure because it prevents overwintering pests from emerging alongside your newly planted seedlings. Clearing away vines at the end of the season will help prevent them from overwintering in the first place. Once your vine is done for the season, cut at the base as close to the soil level as possible. The roots can be left in place to add organic matter to your soil, while the rest of the material should be discarded. It is not recommended to compost these if you suspect a potential pest issue. 

With most of these pests, the best defense is a good offense. Be vigilant and inspect your squashes often. Squash beetle eggs are particularly easy to spot. They lay their eggs on the undersides of the leaves, and they appear small, oblong, and bronze. It’s easy enough to squish them between your fingers. Adult bugs can be picked and dropped into a bucket of soapy water to kill them. They also make an excellent snack for your chickens. 

Diseases

Overwatering can cause the perfect conditions for fungus to take hold, especially in hot and humid climates. Too much moisture splashed onto the foliage during watering can contribute to issues with downy mildew. 

Downy mildew is often mistaken for powdery mildew, but it appears as yellow spots on the tops of the leaves with black spore masses on the undersides. In contrast, powdery mildew appears as more of a white flour-like powder on the leaves. 

To prevent these issues, always bottom water your plants; neem oil may also be sprayed as a preventative measure to reduce the colonization of spores on foliage. In advanced cases of this mildew, it may be best to remove and destroy infected plant material to prevent it from spreading to nearby healthy vines.

Frequently Asked Questions