Timely Tips and Instructions for Growing Giant Pumpkins:
It’s time to think of Halloween pumpkins if you want to grow a giant one. The longer it’s growing, the bigger it’ll get, so start soon!
- Select a Site in full sun. Growth relates directly to the amount of sunlight. They need 8 to 12 hours every day.
- They need space. Each hill (cluster of three to four plants) should be spaced 35 to 50 feet apart, if you are planting more than one hill.
- Soil must be rich and well prepared. The best pumpkins come from the best prepared soil. Dig a hole 3 to 4 feet deep and 3 to 5 feet in diameter and mix the soil well with six to eight bags of soil amendments or conditioners. Include steer or horse manure that is one or more years old. Put the mixed soil back in the hole. You should now have a mound two to five feet in diameter and 16-18” high at the center.
- Germinate Giant Pumpkin Seeds.
- Soak seeds overnight 8-12 hours in warm water. This softens the shell and accelerates germination. Start this mid-April to mid-May. If you have a warm, sunny environment, like a greenhouse or cold frame, you will get substantial growth before transplanting, so use a container that will hold enough seed germinating soil mix such as a 5” or larger pot or a flat of soil 2” deep and 18” X 18”. Keep moist and warm 75 to 80 degrees F is ideal. Special seed germinating soil cables under the flats or pots will hasten the process. The cable is also useful for starting cuttings of other plants. This special cable is water resistant and is safe, avoiding electrocution. Plug in to a protected ground fault interrupted plug for further safety. Do not use sharp tools in the soil once the cable is in place. To keep the cable for years of growing, clean it off and store it dry between uses.
- Under these conditions, the seeds should sprout in 4-7 days, sometimes even sooner.
- After the seedlings have developed one or two true (large and veined) leaves, the plants are ready to transplant into the mound.
- Alternatively, you may just plant the seeds directly in the mounds once the soil has warmed up later in the season. Competitive giant pumpkin growers have successfully used both methods.
- Transplant on a warm, calm day or in the evening to reduce dehydration. Plant the seedling peat pot and all in the center of the mound, making sure the peat pot is well below the surface of the mound. Use care to minimize soil compaction with your weight. You can distribute your weight across a sheet of plywood or large, lightweight board.
- Protect your new plant from earwigs with rolled up newspaper or earwig bait or put a cardboard box with the top and bottom removed to also protect from rodents and wind. Take off once the seedling is fully established, usually 7-10 days.
- Watering, Fertilizing and Care.
- Pumpkins are 90% water, so the soil should be kept fairly moist. Do not keep the soil saturated, though as disease problems might arise. Water daily to once every 2-5 days depending on your weather and soil conditions. Watering times should be consistent. The best time to water is early mornings 5 to 8:30 am. If you can't make that time, the next best time is late afternoons/early evenings.
- Use organic fertilizer every 5-10 days. Seaweed kelp and/or fish emulsion are some of the fertilizers being used by competitive Giant pumpkin growers.
- Mulch around the main stem with bark, compost, straw or well aged manure 3-4” deep. Leave 9-12” air space around the stem to avoid rotting it. Mulching will help regulate soil temperature and retain moisture around the main stem and primary root system.
- Place a wooden pallet under the pumpkin before it gets too big and too difficult to move (10-25 pounds) to keep the pumpkins bottom from rotting, and to facilitate lifting and transporting later.
- Shade the pumpkin once it reaches 24” to 36” diameter to keep the skin from burning, hardening and cracking from the hot, mid-late summer/early autumn sunshine. The pumpkin expands very quickly during this last growth phase, so protect the flexibility of the skin with shade. Short of building a miniature shade house, you can use cheese cloth over the fruit or carefully cover the pumpkin with its own leaves. Be very careful not to break the vine.
- I’ve carved larger pumpkins with a small electric chain saw. It works great on the extra-thick rind. The world record is 1,725 pounds set last year in Ohio.
Article by Stuart Shim copyright 2008
Edited by Ken Brizzi 2010