How to Grow Epic Pumpkins in Raised Beds
Although pumpkins take up a lot of space, you can still grow them in raised beds. Join farmer Briana Yablonski to learn how to grow these cucurbits in your garden.
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Whether you dream of carving a homegrown Jack-o’-lantern or serving friends warm bowls of pumpkin soup this fall, pumpkins are a must-have in your garden. Their long vines and iconic fruits make them an impressive addition to any space, including raised beds. And since so many different varieties are available, you can brighten your space with orange, gold, white, and blue versions of this winter squash.
Since pumpkins grow long vines, you may be hesitant to grow them in raised beds. However, these plants can thrive in garden beds as long as you provide them with full sun, the proper nutrients, and enough room to sprawl. Keep reading to learn pumpkin growing basics as well as some expert tips and tricks.
Choose the Correct Raised Bed
When it comes time to choose a raised bed, you have all kinds of options. These garden beds come in various heights, widths, and materials, which can make it difficult to decide which one is best for you and your needs.
Since pumpkins develop extensive root systems and produce vines that grow over five feet long, look for a raised bed that’s at least 12 inches deep and two feet long by two feet wide. If you want to grow more than one plant in a single raised bed, look for a bed that’s at least four feet long. This spacing will allow you to grow the plants three feet apart with a bit of space between them and the ends of the bed.
As far as bed material goes, one option isn’t necessarily better than the other. Just look for non-toxic products that will stand up to the moisture and fungi present outdoors. Metal raised beds and untreated cedar beds are two great options.
Select Your Variety Wisely
Although bright orange pumpkins are the most popular, you can find handfuls of different varieties of these winter squash. Some produce sweet-fleshed fruits that work well in pies and soups, and others churn out ridged and knobbed squash that serve as unique fall decorations.
Along with paying attention to the fruit’s characteristics, take note of each variety’s growth habits. Almost all pumpkins produce vines, but these sprawling stems vary in length; some vines remain under five feet long, while others can exceed 20 feet!
In general, the larger the fruit, the longer the vine. Therefore, you should look for a compact variety if you’re working with limited space.
Pumpkin Varieties to Try
Some great varieties for raised beds include:
- ‘Lumina’: Small, round, white fruits that work equally well for carving and baking
- ‘Sugar Pie’: Small, orange pie pumpkins perfect for stuffing or baked goods
- ‘Big Max’: A great choice if you want to grow a giant pumpkin
- ‘Black Kat’: Cute, black fruits perfect for Halloween decor
- ‘Galeux d’ Eysines’: Large warty squash work well for eating and decoration
Seed cultivars also have different disease resistance. Some plants are resistant to powdery mildew, which often infects the green leaves and sprawling vines.
Don’t forgot to look at the days to maturity (DTM). Pumpkins are generally ready to harvest between 85 and 125 days. If you live in an area with a short growing season or are planting later than you wished to, opt for a faster-maturing variety to ensure your plants have enough time to grow. These are usually small-fruited types.
Amend the Soil as Necessary
One of the great parts about growing pumpkins in raised beds is how easy it is to create productive soil. Even if you’re starting with heavy clay or rocky ground, you build a raised bed on top and fill it with a well-draining, nutrient-rich soil mix. Many types of raised bed soil are available, so look for a blend that balances water-holding with drainage and contains beneficial microorganisms and necessary plant nutrients.
Even if you started with well-balanced soil, you may need to amend it before planting your pumpkins. Remember that plants take up nutrients as they grow, so you remove nutrients from the soil each time you remove crops from the garden. Adding fertilizer between growing seasons and crops ensures your plants have the nutrients they need to thrive.
Pumpkin plants use a lot of nitrogen to form their expansive vines, so add some feather meal, blood meal, or other nitrogen-rich fertilizer before planting. Once the plants are large and lush, switch to a fertilizer higher in phosphorus and potassium to encourage flowering and fruit production.
Along with adding specific nutrients, I recommend adding a few handfuls of biologically rich compost or worm castings. These products will add beneficial microbes to the soil and, in turn, improve plant nutrient availability, disease resistance, and soil structure.
Plant at the Right Time
When you think of winter squash and pumpkins, you probably imagine them alongside changing leaves, cooler days, and holidays like Halloween and Thanksgiving. Although many people enjoy these fruits in the fall, the plants grow best during hot and long summer days.
Since these cucurbits are sensitive to frost, wait until cold spring weather has passed before planting them outside. It’s fine to direct seed after your last frost date, and the large seeds germinate quickly as long as you plant them an inch deep and keep the soil moist. However, you can also start the seeds indoors a few weeks before your predicted last frost date. Transplant the seedlings into your garden after the weather has warmed.
Depending on the variety you’re growing, expect the plants to take two and a half to four months to mature. If you sow the seeds in the middle of June, you can expect to harvest fruits sometime between early August and mid-September. If you wait too long to sow your seeds, the plants may not have enough time to mature before the first frost arrives.
Keep an Eye Out for Pests
Like all types of squash, pumpkins are susceptible to a few major pests in regular or raised beds. Knowing which pests to look for will help you identify and treat them quickly.
Squash Bugs
These true bugs have elongated, flattened bodies, and the adults appear in shades of brown and gray. Adults lay clusters of shiny, bronze eggs on the underside of cucurbit leaves, and the eggs hatch into gray nymphs. These nymphs molt multiple times before turning into adults about four to six weeks after hatching.
Both nymphs and adults pierce squash leaves and drink the plant’s sap. A few squash bugs can cause wilted leaves, and large numbers may lead to plant death.
One of the best ways to keep your plants safe from squash bugs is to regularly scout for these destructive pests. Crush any adults and nymphs or place them in a container filled with soapy water. Make sure to turn over the leaves to look for eggs and scrape off any copper discs you see. At the end of the season, remove any cucurbits from the garden to discourage pests from overwintering.
You can also create an environment that attracts natural predators like the feathered-leg fly (Trichopoda pennipes). Planting a diversity of flowers will provide food for the adults and encourage them to lay their eggs on the squash bugs.
Squash Vine Borers
As its name suggests, the larval form of this moth bores its way into cucurbit vines. Once the larvae are inside the vines, they begin feeding from the inside out. Their damage disrupts the flow of water and nutrients, which can quickly cause their host plants to wilt and even die.
If you see wilting leaves, examine the base of the plant’s stem. Small holes surrounded by sawdust-like material indicate that a vine borer is likely inside. Use a sharp knife to cut the vine, and then extract the larva. Cover the cut stem with soil to encourage it to form new roots.
Since the moths lay their eggs from the beginning to the middle of summer, another option is to cover young plants with row cover. By the time the squash starts to flower, you can remove the cover without worrying about the pests. However, don’t use this control method if you grew cucurbits in the same bed the following year. The pests overwinter underground, so covering the plants may trap emerging pests.
This video explains more strategies:
Encourage Good Airflow
Squash plants are susceptible to numerous fungal diseases, including powdery mildew, downy mildew, and anthracnose. Since most of these diseases are more likely to occur on damp leaves, make sure to encourage good airflow to keep the leaves dry.
Most pumpkins prefer to be spaced two to three feet apart within your raised bed. Unless you have a bed that’s at least six feet wide, you should only grow one row of plants per bed.
Plant your pumpkins in an area that receives at least eight hours of daily sun. Morning sun is preferable to afternoon sun because it dries out any morning dew collected on the leaves.
Control the Plant’s Spread
One of the major challenges of growing these plants in raised beds is handling their sprawl. Even if you grow a compact variety, you should expect the vines to reach four or five feet long. And remember that some varieties can produce vines that grow over 15 feet!
To Trellis or Not to Trellis
Since pumpkin plants only form roots at their base, there’s no need for all of the vines to grow in rich soil. It’s fine if the vines sprawl over and out of the raised beds, so there’s usually no need to trellis. However, the rambling vines can easily take over grass pathways you need to mow or smother veggies and flowers growing in other garden beds.
If you’d like to keep your plant off the ground and prevent it from overtaking other parts of your garden, you can train it to grow up a trellis. These plants produce green tendrils that help them hold onto supports and allow them to grow vertically.
Types of Trellising
Many trellises can work well, providing that they’re strong enough to support the weight of the stems and leaves as well as the heavier fruits. Cattle panels are easy to find and have thick enough wire to hold the vines and fruits. You can secure a panel to one side of your raised bed or use multiple panels to form an arch over the bed.
You can also train these cucurbits to grow up and over wooden arbors or chain link fences. However, avoid trellising with string since twine will likely snap under the weight of the plants.
Varieties that produce larger fruits may need a bit of extra support to prevent them from snapping off the vine. Grab a piece of pantyhose or a mesh bag with enough extra room to contain the fruit as it grows. Tie it around the small pumpkin and attach it to the trellis. When you’re ready to harvest, just cut the support off the fruit.
Keep the Soil Moist
Since pumpkins are large plants, they require lots of moisture to grow well and remain healthy. Strive to keep the soil consistently moist throughout the growing season. Alternating between wet and dry soil will stress the plant and cause problems with fruit development.
Any watering method will work well as long as your squash receives the water it needs. However, avoid watering the leaves since this can encourage fungal diseases to develop. Setting up a drip irrigation system makes it easy to apply water directly to the base of your plant, but you can also use a hose to water.
Mulching the soil with leaf mulch, wood chips, straw, or another type of organic matter is an excellent way to conserve moisture. The mulch will also help limit weeds from popping up between the sprawling vines. It will also prevent the fruits from growing directly on the soil and thereby limit the likelihood that they’ll rot in the field.
Protect Fruits from Critters
It turns out humans aren’t the only ones who like to eat pumpkins! Mammals like groundhogs, squirrels, rabbits, and raccoons all enjoy the fruit’s sweet and starchy flesh. If you’re not careful, a ripe pumpkin can go from picture-perfect to half-eaten overnight.
One way to protect the fruits from large pests is to physically exclude the animals with fencing. However, be aware that smaller mammals can often find their way through even the tiniest of holes. And burrowing mammals like groundhogs and gophers can tunnel through the bottom of raised beds unless you cover them with mesh or wood.
Another option is to sprinkle cayenne pepper around your garden or spray the fruits with hot sauce. These substances contain the undesirable compound capsaicin and help deter mammals.
Harvest at the Proper Time
After caring for your plants all season, harvest time is always an exciting moment! Fortunately, picking pumpkins is easy. Just wait until the fruit looks mature and has developed a thick skin. Use a pair of clippers or a knife to cut the stem an inch or two above its base.
If you want to store your fruits for more than a week or two, take the time to cure them. Curing involves placing the fruits in a warm, sunny, and dry location for one to two weeks. If the weather is dry and the temperature remains between 80°F and 90°F (27-32°C), you can leave them in your garden to cure. However, you can also place them in a greenhouse, sunroom, or other suitable location.
Adequate airflow is crucial for preventing mold, so adding a fan is always a good idea. Once the fruits have developed a hard skin, store them in a dry area with a temperature between 50°F (10°C) and 70°F (21°C).
