1. Choose Pumpkins Wisely
Pumpkin plants can be quite different from each other, depending on variety, so it’s important to select the right one for your climate and available space, advises Darrell Geissler who grows thousands of heirloom and hybrid pumpkins on his farm in Iowa. For example, in short-season areas in northern regions, it’s best to grow quicker-maturing varieties or start them early indoors. And some larger varieties such as ‘Jack-o-Lantern’ can grow vines as long as 17 feet so they need plenty of space to ramble. Smaller bush or semi-bush types grow vines about 5-10 feet long so are better for more modest-size gardens. And while all pumpkins are edible, some taste far better than others. If your aim is to raise pumpkins for baking and cooking, make sure to select varieties such as ‘Sugar Pie’ that have a sweeter flavor and smoother texture.
2. Pay Attention to Harvest Times
Seed packets of pumpkin varieties will list the days to maturity, which means the number of days you can expect it to take for the plant to go from a seed to harvest. Then, do the math to figure out when you need to start your plants so that they will have the required number of days free of any frost. For most regions, if you wanted to grow a variety that takes 100 days to mature, for example, starting those seeds between May and June would do the trick.
3. Give Pumpkins Enough Sun and Space
Pumpkins love spending their days in the warm sun so plant them in a spot that sees sun all day long. If your only options don’t offer all-day sun, somewhere that gets at least 6 hours of direct sun a day can work. Make sure you have anywhere from 5 to 20 square feet (depending on variety) to allow the plants to vine out. For smaller varieties, it is possible to train them onto a trellis, which can help maximize your growing space.
4. Set Seedlings Up for Success
Wait to plant until the daytime temperatures in your area reach the 70s and the nights are frost-free before planting pumpkins. You’ll also want to add generous amounts of compost or well-rotted manure to the planting area and dig it into the soil. This helps loosen the soil, so pumpkin roots will have an easier time getting established. Compost also helps your soil retain moisture and boosts nutrient levels, two things pumpkins need in ample amounts. Once you’re ready to plant, create a pumpkin hill (a low mound of soil) and sow three to five seeds in it, evenly spaced from each other. The seeds will germinate in about a week. When they reach about 4 inches tall, snip off all but the most robust couple of seedlings in each hill. If you leave the seedlings crowded together, the plants won’t be as strong and their fruits won’t be as big as they could be. In cold climates (Hardiness Zones 2-5), give plants a head start by sowing seeds indoors and transplanting them into the garden in early summer.
5. Keep Plants Well-Watered and Fed
Pumpkins are made of up to 90 percent water, so give your vines plenty of moisture, especially during hot summer weather. Geissler recommends not watering right at the base of the plant, which can lead to stem rot if you overwater and that will kill your pumpkins. Instead, direct water in a 2-foot circle around the plant, and the roots will find their way to it, he says. Also, try to avoid getting water on the leaves to help keep powdery mildew at bay. This fungus not only damages leaves, but it can also get into the fruit and ruin it. If you’re looking to grow pumpkins long-term, a drip irrigation system might be a good investment to help avoid diseases. Pumpkins are “heavy feeders,” meaning they need lots of nutrients to fuel all their growth and the development of their large fruits. In addition to adding compost before planting, use compost as a mulch around your plants once they’re up and growing. Most varieties will do just fine with this treatment, but to ensure the largest pumpkins, water with a liquid fertilizer formulated for vegetables ($20, Walmart) once a week.
6. Control Pumpkin Pests and Diseases
Pumpkins need pollinators to set fruit, so let bees do their work and don’t use insecticides. Pick off squash bugs (they look like stinkbugs) and their golden-orange eggs, which may appear on the undersides of leaves. Control powdery mildew with sulfur dust or spray.
7. Treat Pumpkins Carefully at Harvest Time
As vines start dying back toward the end of summer, pumpkins are ready to pick when their skin colors fully develop and the stem is a deep green color. The skin also becomes leathery. If you poke it with your finger nail, it will spring right back, says Geissler. To help a harvested pumpkin last longer, Geissler recommends not cutting it off the plant at the stem. Instead, he cuts the vine on either side of the stem with a clean knife or pruning shears. Those cuts heal over better, which helps the fruit hold in moisture and keep out fungi and bacteria that will rot it. Pumpkins with their stems attached tend to last longer than those without, so be careful not to break it off (always lift it from the bottom). Geissler also washes the outside of his pumpkins with a 1-2% solution of bleach and water (add one or two parts bleach to eight or nine parts water) to stave off rot. He advises rinsing them off and setting your clean and dry pumpkins in your garage or basement until you want to use them. He’s had pumpkins last more than a year when properly harvested and kept in a cool, dry place.
