Few other vegetables are more representative of fall than pumpkins. Come October, mounds of pumpkins of various shapes and sizes are a common sight in Napa Valley. While they may seem to suddenly appear, pumpkins have a fairly long growing season. If you are considering growing pumpkins in your garden for a fall harvest, it's time to plant.
Pumpkins belong to a large botanical family that includes melons, cucumbers and other squash. Some tiny pumpkin varieties can fit in the palm of your hand. The record-setting types weigh in at over a ton. Pumpkins also come in shades beyond jack-o-lantern orange. For an unusual addition to your garden, seek out white, red or blue-skinned varieties.
One bonus of planting pumpkins is that they attract bees. Honeybees will happily do the work of pollination, but a garden with a range of plants will lure and nurture other bee species. Squash bees tend to fly early in the morning, before honeybees get going. You may never even know that they have visited your garden. To encourage squash bees, consider adopting a no-till regimen. Squash bees nest several inches below the soil, and frequent tilling can destroy their habitat and nesting populations.
It is a joy to watch pumpkins grow, but they do need space. If your garden has ample room, allowing the plants to ramble can help shade and cool the surrounding soil and prevent weeds from growing. Before planting, amend the soil with compost to get plants off to a healthy start. Plants can be started in small pots or direct-seeded. If you are aiming for maximum size, feed with a high-nitrogen fertilizer to stimulate leaf growth. When blooms appear and fruit set occurs, phosphorus and potassium become more important.
Once established, pumpkins grow fast. To promote larger pumpkins, select one or two good specimens and remove all others on the vine. This pruning will help the plant transfer nutrients to the remaining units.
Squash leaves can be susceptible to mildew. Irrigating with drip or soaker hose is preferable to overhead watering. Remove diseased leaves as soon as possible and do not overwater. Leaves may wilt on hot days but typically recover as the weather cools. If wilting persists, check to make sure plants have adequate water
Common pumpkin pests include cucumber beetles and vine borers. A home gardener can tolerate some damage rather than resorting to chemical sprays. Remember that pollinators and other beneficial insects might be frequenting the plant, too. Use light-permeable row covers to protect plants if an infestation is particularly heavy.
Trap crops can also help reduce insect damage by providing an alternative food source. Crop rotation can help by eliminating available food sources for future generations of pests. The University of California's Integrated Pest Management database is an excellent resource for pest- and disease-control advice.
Besides being delicious, pumpkins have other advantages for the home gardener. They can help minimize weed growth around taller plants such as sunflowers. Native Americans understood the wisdom of planting pumpkins with beans; the beans add nitrogen to the soil and pumpkins are heavy feeders. Many pumpkins store well and can provide tasty meals in winter when many vegetables are out of season.
You don't have to wait for the pumpkin to mature before enjoying the plant. The leaves are edible and can be cooked like spinach. Choose young, tender leaves for that purpose. Of course, the seeds are edible, too. Enjoy them roasted and salted to increase the food value of your crop, particularly if you have limited space. Saving seeds and swapping with friends can increase your garden's diversity with no extra expense.
Pumpkins grow well in Napa Valley. Consider planting a beautiful heirloom cultivar to enjoy as a table centerpiece in winter. Between the pumpkin's tasty flesh, its seeds and its nutritious leaves, this plant hits a triple.
Workshop: U.C. Master Gardeners of Napa County will hold a workshop on “Succulent Plant Success” on Saturday, July 7, from 9:30 a.m. to 11:30 a.m., at University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Bring your love of succulents to this workshop dedicated to helping succulent gardeners grow the show-stopping plants we all hope for. Master Gardeners will show you the right kind of soil and containers and how to care for your succulents. They will also discuss myriad succulent types to help you make a succulent garden for yourself or to give as a gift. Please bring succulent cuttings you would like to share.Online registration (credit card only); Mail-in/Walk-in registration (check only or drop off cash payment).
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.