October 30, 1998
For many of us, pumpkins are a "must have" in our gardens. Certainly they're not the most practical use of garden space. Not only do the vines spread like mad, but cost-wise it doesn't really add up either. We grow them anyway, though, because frankly they are just plain fun!
True pumpkins are of the botanical species Cucurbita pepo, which also includes all summer squash and some winter squash like Delicata and Acorn. However some big pumpkins, like Dill's Atlantic Giant, are actually squash of the species C. maxima. So what makes some C. pepo squash while others are true pumpkins? Unfortunately, to the best of my knowledge there is no cut and dried explanation. The differentiation between a pumpkin and a squash seems to be more a question of appearance and use than anything else. For the majority of non-taxonomists, however, this is pretty much moot. The culture of all squash and pumpkins is basically identical.
Pumpkins like to grow in a warm, fertile, well-drained soil. It is a good practice to grow a green manure crop over winter preceding the pumpkins. The seeds do not germinate well if the soil temperature is much under 60F. Also the plants need a nice, long, warm growing season to set fully mature fruit. Unfortunately our spring soils can be rather cool well into June. If we get a warm spell in May pumpkins can be direct sown in the garden. However I've found it more reliable to start them inside, in individual four inch pots, in mid-May. Doing this does not give you much time to procrastinate, however, since they go from seed to a good-sized plant in under three weeks! All cucurbits are touchy about transplanting - do not let them get rootbound, and handle them carefully when you take them out of their pots.
Whether direct seeding or transplanting, work about a cup of a complete organic fertilizer into each spot where a plant will be growing. The common wisdom is to grow two pumpkin (or squash) plants in each spot, but I've experienced earlier fruit set and good yield by thinning to one plant.
Once your plants are growing, very little will bother them. Cool wet weather can be problematic, both because the vines don't grow well in those conditions, and slugs love the young plants. A common problem towards the end of summer is powdery mildew, a fungus that spreads in dry conditions. Sulfur can be used to control it, but in my garden the powdery mildew doesn't get bad until late in summer anyway. By that time it is close to first frost, and the vines aren't doing much. Pumpkin plants do not tolerate frost.
It is wise to choose your pumpkin varieties according to what you wish to do with them. Do not use jack-o-lantern types for pumpkin pies - they are bred for yield, and not for flavor. Small Sugar is probably the best pie pumpkin. The classic jack-o-lantern pumpkin is Howden. A very beautiful pumpkin (actually a squash) is the heirloom Rouge Vif D'Etampes, which is the pumpkin coach of the Cinderella story.
If you want to grow giant pumpkins there are a few principles for success. First, start with a variety that's been bred to produce large fruit, such as Prizewinner or the afore-mentioned Dill's Atlantic Giant. Start the plant early, and keep it well-fertilized and well-watered. People who are serious about this will actually dig huge holes and then fill them with a custom-made mix that allows rapid root growth and provides abundant nitrogen. Finally, thin each vine to one fruit per plant, and remove any additional baby pumpkins that form.
Hopefully this article will help you to successfully grow your pumpkin patch. Remember that, in order to attract the Great Pumpkin, you'll have to provide one other component. According to Linus Van Pelt, the famous pumpkin authority, that ingredient is sincerity.
All contents © Travis Saling
This page was last updated November 18, 2013