Answers to Your Questions About Pumpkins

Answers to popular pumpkin questions

Q. I have a pumpkin plant. I want to carve my son's name on a pumpkin when it's small so that the pumpkin (and his name along with it) will grow large. What size should the pumpkin be? What's the best tool to use? At what depth should I carve his name?

A. It will depend on the variety of the pumpkin and its eventual expected size. You can begin writing on small varieties as soon as they are the size of a tennis ball. Bigger varieties may go up to a basketball in size before you need to do the monogramming. It doesn't take much – just enough poking with any sharp pointed instrument to break the skin of the fruit. A closely-knit series of poked dots (rather than cursive or calligraphy) is the most effective technique.

Source: National Gardening Association

Q. How can I grow pumpkins that weigh more than 100 pounds?

A. Use one of the jumbo varieties. Plant in early June, and allow 150 square feet per hill. Thin out the best one or two plants. High fertility, proper insect control and shallow cultivation are essential. Remove the first two or three female flowers after the plants start to bloom so that the plants grow larger with more leaf surface before setting fruit. Allow a single fruit to develop and pick off all female flowers that develop after this fruit has set on the plant. Do not allow the vine to root down at the joints near this developing fruit because these varieties develop so quickly and so large that they may actually break from the vine as they expand on a vine anchored to the ground.

Tips for Growing Giant Pumpkins

  • Soil prep, most important factor, after testing and adjusting soil use large quantity of partially decomposed compost.
  • Start seeds in pots early to provide for longest growing season for your zone. Move seedling to warm outside soil and temperatures 65°F or provide mini-greenhouse.
  • Fertilize, first with higher phosphorus for roots, later with balanced fertilizer.
  • Water, fortifying with liquid fertilizer, growing pumpkins requires gallons of water.
  • After pumpkins start growing, limit vines to one or two. Be ready to adjust vine positions as pumpkins grow larger
  • Make sure pumpkins get as much sun as possible.

Q. We would like to try growing mini pumpkins this year and train the vines to grow up a tomato plant wire cone. Is this a good idea? Any advice on seed types? What can we do to keep the mold away?

A. We've grown Jack-Be-Little pumpkins on a wire tunnel so children can crawl under the vines. The vines stay up on the top and the mini-pumpkins hang down through the wires. It's great if you're a little one! Mini-pumpkins require the same culture as regular-sized pumpkins: lots of sunshine, plenty of water and enough elbow room to provide good air circulation. If you're having trouble with mildew and mold on the leaves, your plants need more sunshine and better air circulation around them. Try not to get the leaves wet when you water, or try to water earlier in the day so the leaves don't remain wet overnight. Jack-Be-Little and Baby Boo are both great little pumpkin varieties.

Q. Will pruning my pumpkin vines back a little harm the plants and result in less pumpkins?

A. Pumpkin vines always grow bigger than we expect! When they escape from the vegetable garden, my husband mows the tips off when he mows the lawn (This reminds me to reroute the vines back where they belong.) It does result in fewer pumpkins because there are fewer flowers on the plant to form pumpkins, but apart from that, in my experience nipping the vine tips with the lawn mower has never set them back noticeably. Cutting them back hard however, would reduce the foliage enough to cut down on photosynthesis and that might make a big difference in the health of the plant and the number of pumpkins it can support. Good luck with your pumpkins!

Q. I grow and sell pumpkins but have had trouble with powdery mildew on the vines. What can be done to prevent and treat this problem?

A. Powdery mildew is a fungal disease. Warm temperatures and dew favor its development. You can help your plants avoid infection by removing some of the vines to increase air circulation among the plants and by directing water around the base of the plants rather than sprinkling water overhead on the fruits and leaves. Early in the season you can cut or pinch off a few of the vines without harming the plant. Wait until some fruits form and then pinch off the ends of the vines. This will increase air circulation and direct the plant's energy into developing fewer, but larger, more flavorful fruit.

Q. I've noticed some gardeners (and a few farmers) who have covered garden areas densely with pumpkins and let them rot over the winter. What is the purpose of this? Any danger of them seeding in the spring?

A. It's never a good idea to leave plant debris in the garden over the winter. The practice seems like a lazy-man's approach to composting. Rotting pumpkins will supply the soil with some nutrients, but will also provide a place for overwintering insects and disease pathogens. Plus, the seeds from the pumpkins will certainly sprout in the spring. This may not be a problem in a commercial field because the debris will be tilled into the soil before the field is planted again. I expect disease problems and errant sprouting seeds are dealt with chemically. But for the home gardener, the stuff will have to be picked up and thrown in a compost pile before the site can be used again. I'd rather handle the plants and pumpkins before they turn into a slimy mess! For the healthiest garden site, compost your end-of-season plant debris and add the compost to the soil before planting in the spring.

Q. Help, my pumpkins think it's fall. They are turning orange and the vines are dying back. What triggers this? Is it lack of sun? They grew in the same place last year. They don't seem to have a disease.

A. There are a couple of reasons I can think of for why your pumpkins would slow down and stop growing. The first is lack of water; pumpkins are water hogs because about 90% of the pumpkin is actually water. Another is lack of nutrients; since they grew in the same place last year they may have depleted the soil in that spot. Third is that some disease has actually attacked; pumpkins are subject to a number of foliar problems which cause the leaves to shrivel; finally, perhaps you are growing an extra-early-maturing variety. (The normal range is 90 to 120 days with the approximate timing listed on the seed package or label.)

In any case, leave them on the vine as long as possible and do your best to cure them as well as you can to try to increase their storage time; depending on the variety and curing and storage conditions, some can be held for up to a year.

Source: National Gardening Association

Q. The first flowers that appeared on my pumpkin plants did not form fruits. Why not?

A. This condition is natural for cucurbits (such as cucumber, gourd, muskmelon, pumpkin, squash and watermelon). The first flowers are almost always male. The pollen on these first male flowers attracts bees and alerts them to the location of the blooming vines. By the time the first female blossoms open, the bees' route is well established and the male flowers' pollen is transferred to the female flowers by the bees. Male flowers bloom for one day, then drop off the plants. The male flowers may predominate under certain conditions, especially early in the season, or under certain kinds of stress. The small fruits, visible at the bases of the female flowers, identify them. There is no swelling on the bases of the male flower stems.

Q. Will pumpkins, squash and gourds cross-pollinate and produce freak fruit if I interplant several kinds in my garden?

A. Pumpkins, squash and gourds are members of the vine crops called "cucurbits." The name is derived from their botanical genus classification of Cucurbita (often abbreviated C.). There are four main species of Cucurbita usually included in the pumpkin, squash and gourd grouping. The varieties within a botanical species (which may be referred to as pumpkins, squash or gourds) can cross-pollinate. Varieties from different species do not. For example, zucchini crosses with Howden's Field pumpkin, acorn or spaghetti squash, small decorative gourds, or Jack-Be-Little miniature pumpkins because they are all members of the same botanical species (C. pepo). However, cross-pollination does not affect the taste, shape or color of the current season's fruit. Crosses show up only if seeds from these fruits are saved and grown the following year. Butternut squash, Small Sugar pumpkin, White Cushaw pumpkin and Big Max pumpkin could all be grown in the same area without crossing because each variety comes from a different species. Because bees carry pollen for distances of a mile or more, in suburban areas where many gardens are in close proximity, fruits must be bagged and pollinated by hand if pure seed of non-hybrid varieties is desired.