Make Sure Soil Conditions Are Right to Grow Organic Pumpkins
Pumpkins need a lot of fertility, especially Nitrogen and Potassium, and dislike very acidic soils. So, before you seed your pumpkins, you will need to make sure that the area where you want to plant them has a soil pH in the neighborhood of 6.0 to 6.5. Pumpkins can tolerate a basic pH of around 7.5, so those of you with alkaline soils can rejoice!
You will also want to add compost or aged manure and a good source of potassium such as alfalfa meal or wood ash (use this sparingly because it can lead to soil salinity problems) to your growing area.
Give Your Organic Pumpkins Room To Grow!
Pumpkins like warm, well-drained soil so they are usually direct seeded into "hills" spaced 5-12 feet apart. The hills are easy to make: just rake some soil into a mound and, if you're so inclined, amend it with compost. Then, plant a few seeds (3-5) in each mound. Once the seeds sprout, thin the seedlings so that you're left with 1-3 plants per hill. You can also direct seed your pumpkins in rows. Pumpkin plants should be at least 2-5 feet apart in rows that are 6-8 feet apart. The spacing will vary according to which variety of pumpkin you're growing: bush or short-vined varieties such as Jack Be Little will need much less space than large-fruited or large-vined varieties such as Howden or Big Max.
If you have a short growing season, and want to grow a relatively long-season variety of pumpkin, consider transplanting your plants. You will have to handle your pumpkin seedlings carefully so that they won't be to set back by the transplanting process: don't allow them to get root bound in their pots, and make sure to keep their root ball intact when you put them into the ground.
Help Your Organic Pumpkins Get Some Fruit on Their Vines!
Protection from wind is a plus for your pumpkin patch. Pumpkin vines dislike being blown around too much. Planting your pumpkins on the leeward (protected) side of a trellis full of tomato or other plants or tall crop such as corn will provide your pumpkins with a lot of shelter from the wind.
Once your plants have germinated and are growing happily, the will flower abundantly. Pumpkins need a lot of pollination in order to set fruit. In fact, a pumpkin flower needs to get eight to twelve visits from a honey bee or other pollinating insect in order to set fruit. Since pumpkin flowers are only fertile for one day, this is a feat that requires an army of pollinating insects to accomplish. Getting adequate pollination is one of biggest challenges that pumpkin growers must overcome.
Fortunately, organic grower's gardens are often havens for bees and other beneficial insects that thrive on the diversity of flowering plants that are available to them in a typical organic garden. More importantly, organic gardeners don't spray long-lasting insecticides that kill pollinators.
Protect Your Organic Pumpkins From Insect Pests and Diseases
When you grow pumpkins, you have to walk a fine line. On one hand, you have to protect your plants from pest insects such as squash bugs and squash vine borers and make your garden less hospitable to these pests. On the other, you have to provide a good home for pollinating insects, such as bees, and allow them to have access to your plants.
Floating row cover, crop rotation and keeping your garden neat and clean are three things that will help keep your pumpkins relatively pest and disease free. Keep in mind that in some areas of the country, such as the humid, buggy, Southeastern US, growing organic pumpkins is an uphill battle!
Covering your young plants with floating row cover and keeping them covered until they flower, will help keep some pests, notably squash bugs, from getting to them before they have a chance to set fruit. Determined growers can even leave the row cover on the pumpkins the whole growing season, as long as they pull it off every morning during the period that the vines are flowering. This will allow the pollinators to get to the flowers while they are open (usually dawn to noon or so) but allow the plants to keep their bug protection during the rest of the day.
Keeping insect pests off of your plants will also help prevent many plant diseases which are transmitted via the pests. Removing diseased or infested plants from your garden promptly (its often better from your pumpkin's point of view to landfill or burn these plants rather than compost them) and keeping the areas around your pumpkin patch mowed will also reduce insect populations and disease pressure.
Harvest Your Organic Pumpkins at the Right Time and Store Them Correctly
At last! Your pumpkins have set fruit and they have grown huge! Ah, what a beautiful sight. Now the trick is to harvest them correctly and then store them until it's time to make Jack O' Lanterns and pumpkin pies. It's best to harvest your pumpkins as soon as they turn orange: the longer you leave them in the field, the more likely they are to get eaten by insects or rodent pests (eww!). Harvest your pumpkins by cutting, rather than twisting, them from their vines. Otherwise you'll end up with a lot of handle-less pumpkins. Keep in mind that pumpkins like hot weather and will suffer chill damage at temperatures below 50
Have a Happy Organic Halloween!
You're pumpkin patch is likely to make you the talk of your block this Halloween. Now, all you have to do is convince your trick or treaters to eat roasted organic pumpkin seeds instead of Snickers bars. . . On second thought, maybe it would be better to just stick with the candy! Happy Halloween!