How to Grow Pumpkins
Whether you are growing them for jack-o-lanterns, Thanksgiving pie or to enter in a contest, pumpkins are fun and easy to grow. Make sure you have a lot of space, though. The vines can grow to 8 feet or more.
The Best Soil to Grow Pumpkins
Pumpkins, like most squash, are heavy feeders which means that they need a lot of nutrients. The fall is a good time to get a soil test done to check for pH and nutrient levels. Skip the cheap soil test kits sold in stores. They are not accurate and only measure a few nutrients. It's best to have your soil tested by a professional lab. Call your local extension office or Master Gardener Helpline to order a soil test kit.
The soil test kit will have instructions on how to sample your soil. Send your sample back to the lab and they will test it and send you a complete profile of your soil. The report will tell you exactly what your soil needs with recommendations for the type of amendments and how much to add to your soil.
Pumpkins grow best in fertile, well-drained soil with a pH between 5.8 and 6.8. Add the recommended amendments and adjust your pH in the fall so that your soil will be ready in the spring. Make sure you have chosen a spot that gets full sun, 10 to 12 hours per day.
When to Start Pumpkin Seeds
Pumpkins need heat to germinate and grow. They also need a long growing season, between 75 and 100 days. If you live in the north with a shorter growing season, you should start your seeds indoors, preferably in peat pots which can be planted directly into the garden when the soil has warmed up so as not to disturb the seedlings' roots. Start your seeds 2 to 4 weeks before your last frost date. Plant them 1 inch deep in the peat pots. Germination should occur in less than a week.
Further south, wait until about two weeks after your last frost date when the soil has warmed to a temperature between 65°F to 70°F to sow your seeds directly into your garden. Pumpkin seeds will not germinate in cold soil. Germination will be the same, less than a week.
How to Plant Pumpkin Seeds
Pumpkin seeds should be planted in mounds in the garden to facilitate drainage. Pumpkins do not like wet feet. A mound acts like a raised bed. The soil will warm faster than the surrounding soil and water will drain faster so that the roots won't be waterlogged.
Plant your seeds 1 inch deep. For regular pumpkin vines, plant 4 to 5 seeds per mound, spacing the mounds 5 feet apart. For miniature pumpkins, plant 2 or 3 seeds per mound, spacing the mounds 2 feet apart.
When the seedlings have developed their first set of true leaves, thin the hills to the best 2 or 3 plants using scissors to cut the stems near the soil rather than pulling them out of the soil so that you don't disturb the roots of the plants that you are keeping.
For seeds started in peat pots, sow seeds 3 or 4 to each pot and using scissors, thin to 1 or 2 plants after they develop their first set of true leaves. The remaining plants can then be transplanted into the garden two weeks after your last frost date.
How to Care For Pumpkin Transplants
In the spring, you may still have cool weather that may affect the growth of your seedlings. It's a good idea to protect your young plants from cool weather using floating row covers. The row covers will also prevent insects from accessing your plants. You will need to keep your seedlings covered for about 6 weeks, until the plants have developed flowers.
How to Pollinate Pumpkins
Pumpkins have male and female flowers. They depend on bees to get the pollen from the male flowers to the female flowers. When your vines start developing flowers, you should remove your row covers so that the bees can reach the flowers to pollinate them.
The vines will develop male flowers first. This attracts the bees so that they are accustomed to visiting your pumpkin patch every day to gather pollen. Two weeks later, the female flowers will appear. You can easily tell male from female flowers. Female flowers are the ones with the tiny pumpkin at the base of the flower. The bees will start visiting the female flowers also and in the process transfer the pollen from the male flowers to the female flowers.
How to Prevent Insects From Attacking Pumpkins
Cucumber beetles and squash bugs love pumpkins. You can keep them away from your seedlings in the spring using floating row covers. After the row covers have been removed, if you must use insecticides, treat your vines late in the afternoon or in the evening when the flowers have closed. Insecticides do not differentiate between "good" bugs and "bad" bugs. They kill all insects that come in contact with them. The following day when the flowers open and bees visit them, the insectides should have dissipated so they will not kill the bees.
How to Water Pumpkins
Pumpkins require a minimum of 1 inch of water a week. Avoid watering from above your vines. This can lead to powdery mildew on the leaves which can kill them. Try to water at the base of each vine. Drip irrigation is ideal.
How to Weed Pumpkins
Because pumpkins are heavy feeders, you want to keep your pumpkin patch well-weeded. Weeds compete with your vines for nutrients and water in the soil. Be careful weeding, though. Pumpkins have very shallow roots and don’t like their roots to be disturbed. Mulch works well to keep down weeds and preserve moisture.
How To Harvest and Store Pumpkins
It’s a good idea to pamper your pumpkins a little by placing some salt hay or a piece of thin board under the fruit while it ripens. This keeps it away from wet soil which could cause it to rot. Pumpkins are ripe when they have reached a deep orange color. Press your thumb against the skin. It should feel hard. Harvest your fruit by cutting the stem from the vine, leaving a “handle” of 3 to 4 inches. Pumpkins need to be “cured” by leaving them in the sun for about a week after you have cut them from the vines. Then they can be stored in a cool, dry basement that maintains a temperature of 55°F.
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© 2013 Caren White