Pumpkins are one of the most colorful and diverse plants in the Cucurbitaceae family, also known as the gourd family. And learning how to grow pumpkins will fill your autumn with smooth or bumpy produce in a rainbow of fall colors!
Along with corn, it is one of the oldest known crops in the Western Hemisphere dating back 7000 years. Originally from the Americas, it was a favorite of colonists who baked it with milk, honey, and spices, creating the precursor to the pumpkin pie as we know it today. A member of the ‘three sisters’ family of plants that were traditionally grown together by Native Americans along with corn and beans, this plant comes in a wide array of varieties.
Today, pumpkins are grown specifically for many special purposes. ‘Sugar Pumpkin’ is a variety bred to be sweet and less fibrous, perfect for pumpkin pies. Micro pumpkins can be found in abundance around Halloween and Thanksgiving as they are perfect for decorating. Giant pumpkins are grown to wow crowds, and carving pumpkins are preferred when it comes to making a jack-o-lantern.
Good Products For Growing Pumpkins:
Quick Care Guide
A beautiful pumpkin nearing ripeness. Source: Elizabeth Cramer
|Scientific Name||Cucurbita pepo|
|Days to Harvest||90-120 days depending on the variety|
|Water:||At least 1 in. per week, more during hot weather|
|Soil||Rich, well-draining soil|
|Fertilizer||Balanced fertilizer 3x/season|
|Pests||Aphids, thrips, squash vine borers, squash bugs, armyworms, cabbage loopers, cucumber beetles, cutworms, flea beetles|
|Diseases||Powdery mildew, downy mildew, gummy stem blight, anthracnose, alternaria leaf spot/blight, septoria leaf spot, cercospora leaf spot|
All About Pumpkins
Pumpkin plants will take over a decent portion of your garden, but it’s well worth it!
From tiny ‘Jack Be Littles’ to larger ‘Atlantic Giant’, pumpkins come in all types. Some, like ‘Small Sugar’, have been bred to have sweeter pumpkin flesh to make pumpkin pies with. Others have been bred for decoration like the ghost (white) pumpkins. Due to the ease with which they cross-pollinate, there are thousands of varieties to choose from. If you have a specific purpose in mind, be sure to look for the appropriate pumpkin variety.
Pumpkins are a part of the winter squash family along with butternut squash and acorn squash. Their seeds are edible, just like other winter squash varieties.
Pumpkin growing is quite easy once you’ve mastered a few key techniques. Pumpkins (Cucurbita pepo is the most common species, although there are a few C. moschata and C. maxima varieties) are vining plants whose vines can reach up to 20 feet in length.
Each pumpkin puts out multiple vines during the growing season each with a long string of flowers that, if pollinated, will become pumpkins. They produce large green leaves that extend off the ground and act almost like a shade to the pumpkins below and have small curling tendrils to anchor the vine in place.
Pumpkin plants put out numerous male and female yellow flowers in an attempt to grow pumpkins. The female flowers are attached to a tiny baby-sized pumpkin fruit and need to be pollinated with the pollen from the male flowers, a taller flower that extends from a stem attached to the vine of the plant. If pollen from the male flower finds its way into the female flowers, the pumpkin has been pollinated and begins to grow.
Pumpkins have a life cycle that lasts 90-120 days depending on the variety. However, if you’re planting pumpkins for Halloween or Thanksgiving, it’s best to start your seeds in early June to be sure they’re ready on schedule.
Many different parts of the pumpkin plant are edible. The flesh of the pumpkin is often used in pies, it can also be fried in the Japanese dish ‘Tempura’ or added to curries. The pumpkin seeds can be removed from the plant and tossed with spices and toasted to create a delicious snack. You can also stuff and deep fry the male and female pumpkin flowers as part of a delicious snack called stuffed squash blossoms. Nowadays, many Americans also like to carve pumpkins for Halloween. Interestingly, before pumpkins were used, the first jack-o-lanterns used to be carved from turnips, beets, or other root vegetables!
Vines can take up a lot of garden space. Source: petahopkins
Pumpkin planting is best done in spring, but in warmer climates, it can be done throughout summer as well. Pumpkin plants need warm soil and growing conditions and do not tolerate the cold well. Be sure when transplanting seedlings that there is no danger of frost, and start your pumpkin seeds indoors.
Growing a pumpkin patch can cause vines to snake their way through a garden quite rapidly. Put your pumpkins in an area where they can take up a great deal of space. Depending on the variety, they can take up to 500 sq. ft.!
Be sure to space pumpkins 2-4 feet apart with ample room for the vines to take off. If they’re too close together, you can accidentally encourage the growth of pests and diseases and make it harder for germination to occur. If you’re looking for a variety that can do well in a smaller space or even in a container, try a micro variety such as ‘Wee-B-Little’ and train it up a trellis.
Plant pumpkins at the same depth that they were at in their starter pot, ensuring they have plenty of soil depth beneath them. Their roots will rapidly grow downward to help them have continual access to water.
As pumpkin vines grow, they’ll start to produce flowers. Once 2-3 female pumpkin flowers have set fruit (become pollinated) on each plant, prune off extra blossoms to focus the vine’s energy on the existing fruit. Pumpkins with too many fruits can result in pumpkins that are not as flavorful or are smaller in size. As the pumpkins grow, keep them off the ground by placing straw mulch or even a piece of cardboard as a barrier between the fruit and the dirt.
A pumpkin vine can be extremely long and have multiple flowers. Source: Elizabeth Cramer
For gardeners wanting to learn how to grow a pumpkin for the very first time, assess your soil and temperature as these plants can be very demanding. Start your pumpkins when the danger of frost has passed in an area where they’ll have the soil nutrients, sun, and water they need.
Sun and Temperature
Pumpkins grow fairly well in zones 3-10. They need full sun and will grow most vigorously once temperatures reach the low 90s. This vine is very sensitive to cold and frost, so be sure that all chance of frost has passed before transplanting out. If necessary, use floating row covers or frost blankets to keep them warm.
Water and Humidity
Pumpkins are thirsty growers and need at least 1 inch of water per week as they grow. Water in the morning to early afternoon, and keep leaves from getting wet to avoid disease. If possible, use a drip line or soaker hose system to deliver water deep into the root system.
When growing pumpkins, be sure not to overwater as it can lead to fungal issues and rots. While it may be tempting to water in the late afternoon when the wide leaves are wilted, hold off. The leaves are not necessarily wilted due to a lack of water. During a few hours in the hottest portion of the day, water evaporates out of the pumpkin leaves at a rate faster than it can absorb water through its roots. Stick with a morning watering regimen while pumpkin farming and your vines will thrive.
When growing pumpkins, space them at least 2-4 feet apart in well-draining, loamy soil. If growing in sandy soil, be sure to water more frequently, or work in some extra organic material to help hold moisture. Compost or manure is ideal, as pumpkins are very heavy feeders and will love the extra nutrients.
Pumpkins need soil with a minimum soil pH of 6.5 but prefer 6.5-7.0.
Pumpkin flowers are bright bursts of color. Source: Elizabeth Cramer
An annual addition to the garden, pumpkins need fertilizing three times throughout their life cycles. While young, apply a balanced fertilizer to get your new vine started off right. Before the fruit sets, add a balanced fertilizer to provide a little extra phosphorous and potassium as well. Finally, do a third fertilizer application partway through fruit development. Be careful not to over-fertilize, as this can cause its own problems!
It’s not just for aesthetics that pumpkins need to be trimmed. A pumpkin’s fruit increases in quality if there are just 2-3 growing per plant. Pumpkins will produce male flowers first, then female flowers on the vines, and the male flowers can remain, but excess female flowers may need to be removed once some have been pollinated and start to set fruit.
When a vine reaches 15-20 feet in length and begins to grow secondary and tertiary vines, clip back the main vine to near where the pumpkins are growing. This will slow its outward growth.
When multiple vines sprout from the larger main vine, only allow 2-3 vines to grow and produce. Be careful not to prune too soon, as cutting the vines before the fruit has set can limit the amount of pumpkin fruit you will get.
Most pumpkins are grown from seed, however in some circumstances rare and giant pumpkin growers are known to root cuttings from plants. This is unnecessary for the average grower looking to grow an established variety.
To grow from pumpkin seeds, start seeds indoors in trays. If you want to direct-sow, soak the seed for 24 hours and then sow into small hills or mounds.
If rooting a cutting, dip tip into rooting hormone and place in soil mixed with vermiculite. This can be tricky and prone to failure, and the cutting won’t produce until the following spring and summer season. This is a process best left to people who already know how to grow pumpkin plants very well!
At the end of the season, cut the vines back to the soil and remove any diseased foliage from the garden. Non-diseased material makes a great addition to your composter.
Harvesting and Storing
Leaves provide protection for the developing fruit. Source: jennybach
Whether using for decoration, carving, or eating, all pumpkins require a little patience on the part of the grower. Wait until the stem dries before harvesting. Harvesting too soon can cause disappointing flavor or decorations that will rot quickly.
It’s time to reap the rewards of your hard work when the pumpkin stem turns a pale tan color, and the rind of the pumpkin has hardened.
Harvest your pumpkin fruits by cutting the stem 2-3 inches away from the fruit. Leave the pumpkin in place for at least two days to let the cut stem dry. If storing pumpkins’ fruit for the winter, leave the pumpkins outside for a week to cure before bringing indoors. Wash the rind before bringing inside with a mix of one gallon of water to 1 Tbsp bleach mixture. This will kill any fungi or insects that may linger on the fruit.
Sugar pumpkins will last 1-3 months inside in a well-ventilated space. If stored in a pantry, check regularly for signs of softening and rot. Make sure that not too many are stacked on top of one another as this can hasten decay.
Smaller decorative pumpkins can be kept for 2-3 months on counters and tables. You may wish to put a protective layer between it and the surface it’s on as they can rot from the bottom first.
If choosing to freeze pumpkins, it’s best to peel, deseed and chop pumpkin before doing so. Freeze on cookie trays and once frozen, condense into gallon bags. If pressure canning pumpkins, be sure to follow a tested and safe canning method for preservation to avoid botulism and other food-borne diseases.
Pumpkin seeds can be cleaned and either saved for the following season or roasted with spices as a snack. To save them for later planting, allow them to fully dry out in a cool, dry and well-ventilated location.
A tangle of vines can encircle a growing pumpkin. Source: kevinptrovini
Several different problems can cause a lackluster harvest. It’s important to identify these issues quickly to fix them before they can destroy your planned growing season.
Sunburn is a surprisingly common problem for pumpkin growers, especially early in the season. Make sure to plant pumpkin vines after they’re fully hardened off to outdoor conditions when possible. If you have to get them in the ground a bit early, make sure they have shade during the hottest part of the day and gradually increase their sunlight exposure.
Excessive nitrogen is a pretty common issue. This can manifest as gigantic leaves, massive vines, and little to no fruit. Leaves may also split because they’re growing faster than their own tissues can tolerate. Avoid overfertilization.
Underwatering is one of the biggest problems a vine can face. Too little water results in vine stress that can manifest in a number of ways. Leaves may yellow or brown, the vine can have less vigor, and fruits can actually rot on the vine. Make sure your vine has consistently moist soil and gets watered at ground level at least once a day.
Spray damage is fairly common as well on the pumpkin plant. Pumpkins’ leaves are surprisingly tender, for all that they look sturdy. Too hard of a spray, or using too many counteracting products, can produce patterned yellowing and damage to the leaves. Applying products at the wrong time of day is also a major problem. Opt for applying your oils or pesticides in the evening so that they have time to dry overnight. If not, apply early in the morning so they’re dry by the time the plants are in full sun.
If your vine is producing male and female flowers but no fruits are setting, this may be due to a lack of pollination. To artificially pollinate your fruit, use a paintbrush or cotton swab to collect some pollen from a male flower. You can then brush the pollen from into the center of the female flower to pollinate it.
Aphids are very common on pumpkins. While they often don’t cause severe harm to the vigorous vines, they do carry diseases that cause real problems. Insecticidal soap or neem oil can keep the population under control, but for a large outbreak, pyrethrin is a fast form of relief.
Thrips will attack leaves and flowers. On leaves, they produce a stippled yellowing that is similar to the damage caused by aphids, but it’s the damage they cause to the flowers that’s the worse risk. They consume the pollens and interior of flowers, making the blossoms unable to produce pollen or fruit. They also spread diseases. Like with aphids, treat with insecticidal soap or neem oil, and use pyrethrin for big outbreaks.
One of the most annoying pests on a vine is the squash vine borer. As it name suggests, this larvae literally bores into the vine and then eats the soft interior, causing major damage or death. Wrap the vine’s base in either cardboard or aluminum foil to prevent the borer from gaining access, and keep a watchful eye on your plants as they grow. Using BT sprays will kill off adult moths and their larvae, and neem oil or horticultural oil will smother eggs.
The squash bug is a super-spreader on a pumpkin vine. These little black bugs appear in the late summer and cause yellowing leaves, vine wilt, and fruit damage. It’s estimated that because of the gigantic size of the vines, nearly 70% of the eggs laid by these little irritants will go undiscovered, resulting in a sudden population explosion when they all hatch. Coat all leaf and vine surfaces with neem oil to smother eggs, and if you see the squash bug adults, pyrethrin is an effective killer.
Armyworms and cabbage loopers are both moth larvae that will cause holes or skeletonized leaves quickly. If you see these little caterpillar-like larvae, pick them off by hand and drown them in soapy water. BT spray on leaf surfaces is a great preventative.
Finally, a few pests are common on newly-transplanted vines, but as stems mature they become less problematic. Those pests are cucumber beetles, cutworms, and flea beetles. There are different methods to control all of these, so refer to the individual articles on each of those for more info!
Powdery mildew is caused by a fungus that thrives in warm and humid conditions. You can deter it by keeping leaves dry. Remove leaves that are badly infected and spray neem oil on lightly affected areas.
Downy mildew appears as pale white or yellow spots on leaves. It thrives in wet conditions and cool weather and can be fatal to your plant if not treated early. Use a copper-based fungicide to treat.
Gummy stem blight is caused by a fungus that attacks the stem, fruit and leaf of the plant. You might see tan lesions or cankers on stems. It often appears in conjunction with powdery mildew. Use a fungicide to treat immediately and take care not to add infected plants to compost at the end of the season.
Anthracnose develops as tan or brown craters on the surface of the pumpkin. Over time it can quickly devour the entire pumpkin. Treat early as it can devastate the plant if left on it’s own. Use a copper fungicide to control.
Alternaria leaf spot and leaf blight are caused by two different forms of alternaria fungi. Both respond well to copper fungicide sprays.
Both septoria leaf spot and cercospora leaf spot also respond well to copper fungicides.
Frequently Asked Questions
Tendrils help to anchor the pumpkin vines. Source: Faith Unlimited
Q: How long does it take to grow a pumpkin?
A: Depending on the variety, it can take between 3-5 months from seed to fruit.
Q: How many pumpkins do you get per plant?
A: If you’re growing a large variety, you can expect to get 4-8 pumpkins per healthy plant. For a medium to small variety, expect 6-15 or so pumpkins.
Q: Are coffee grounds good for pumpkins?
A: Used coffee grounds are effectively neutral in terms of pH. If they’re unused, they still contain some acids, but if used they’ve leached those tasty acids out to make the popular caffeinated beverage. As a general rule, coffee grounds aren’t bad for your plants, but it’d be best if they were pre-composted first.
Q: Should I put straw under my pumpkins?
A: Absolutely. A thick layer of straw that’s about 2-3” in height can reduce weed spread while keeping your pumpkins off the soil’s surface. You can also opt to place a piece of cardboard under the fruit, but the straw provides padding for the pumpkins.
About the writer, Elizabeth Cramer:
Elizabeth Cramer is a chef, plant lover, and potter. She loves teaching others how to cook and grow their own food. A California native who spent her childhood within earshot of the San Diego Zoo’s orangutans, she now lives by the beach where she battles powdery mildew and farmers’ tans.
Her love of food and where it comes from stems from her time spent living in Spain as an adolescent where she lived downwind from an olive oil factory, biked to school among olive and orange groves, and ate fresh local food. Right out of college she joined community gardens and really began to really fall in love with watching plants grow. A plant obsessive, she’s recently begun canning in an effort to meet her goal of living 100% off of her own land.
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