Dr. Christensenís Pumpkin Growing Secrets

Thatís right I am willing to divulge my secrets. Yes, all of them! Listed below, not necessarily in order of importance, are the secrets of growing a giant pumpkin.
1. There ainít no secrets
2. Good seed
3. Good soil
4. Early season protection
5. Pruning techniques
6. Fertilizing
7. Watering
8. Fruit production
9. Late season protection
10. Hard work
11. Educate yourself
12. Good weather

#1.  There ainít no secrets. Sorry to disappoint everyone that figured there was a quick and simple way to do this. There isnít. Actually without #10 above 2-9 donít matter because it wonít just happen by its self. Iíve heard a lot of wives tales about injecting steroids, injecting sugar, feeding milk and planting on top of dead fish etc. etc. etc. They simply donít work.
#2. Good Seed.  You will never grow a big one with a standard Jack-O-Lantern seed! All of the giants over 300 pounds are of the variety Atlantic Giant. This was developed by Howard Dill in Nova Scotia in the late 70ís. You can buy Atlantic Giant seeds in the supermarket but the quality is suspect. You donít know where the seed came from, who grew it or what the genetics of it are. You are probably asking what are the genetics of pumpkin seeds. I can tell you the great, great, great grandparents of my 777 that I grew this year. By keeping track of the pumpkins genetics, good traits can be selected for and bad traits selected against. Keep track of the name and number of all seeds that you plant and the crosses that you make. Even if you donít plan on growing your own seeds, by keeping track of what you planted it allows the person who gave the seed to you to get an idea of what kind of pumpkin that particular seed will grow.
First, a word on nomenclature. The seed package you received is probably labeled something like 777 Christensen 2004. This means that the seed is from a pumpkin that was grown by a grower whose last name is Christensen, it weighed 777 pounds, and was grown in 2004.  Following that is (927 LaRue x 1016 Daletas). This is the cross of the pumpkin. By convention the female is listed first. My 777 was grown off of a seed from Jack LaRueís 927-pound pumpkin, it was pollinated with pollen from a plant grown from a seed from Steve Daletasí 1016-pound pumpkin. The designation ďDMGĒ stands for damaged, typically meaning the pumpkin had some sort of defect and was not considered a sound pumpkin. For example, my 717 had a blossom end split that went into the center of the pumpkin.
#3. Good Soil. Now you can do as much or as little as you want in this category. If you really want a big one this is where the work begins. This is one of the variables that you do have some control over. The best place to start is with a soil test. This gives you some idea where you are at now and where you may want to be. The key to good soil is lots of organic matter. They say that the best patches have organic matter between 10-20%. Iíve spent six years raising my organic matter from 2 to 6%. It isnít easy and it takes a lot of time. Part of the difficulty is that most of the organic matter decomposes (75% in the first year). This decomposition is what provides the building blocks required to by the plant to grow a giant pumpkin. Manure is great but the fresh stuff can cause problems with too high of nitrogen. I typically put mine on the fall and allow it to age over the winter. Compost is probably even better then manure but is hard to produce in the bulk quanitity that is needed in a pumpkin patch. Leaves, straw, and hay are also a great source of organic matter but if put on in too large of quantities can tie up nitrogen and cause a nitrogen deficiency.
#4. Early Season Protection. Atlantic Giants take between 120 and 150 days to mature. If you look at the calendar we donít have that many frost-free days in this part of Idaho. If you follow the old timers rule of not planting your garden until after the Memorial Day you wonít have a huge pumpkin. Now thatís not saying you canít get a big one. If I have my facts straight Hyrum Benson planted one after Memorial Day and still broke 400#. Most serious growers start their plants the last part of April. Typically I start mine on April 23rd. Within a week the plants are ready to go outside. In order to go out that early they need protection from the frost. I build temporary greenhouses out of PVC pipe and plastic, and even add supplemental heat on those colder nights. Donít build too small of a cold frame as an Atlantic giant can easily outgrow a small cold frame in a matter of a couple of weeks. For first time growers, I would probably recommend starting your plants around the 7-10 of May. This is probably a good compromise between starting too early and having very large plants that are outgrowing a smaller cold frame and starting too late and missing a window for growing a giant.
A word about germination. Atlantic Giant seeds require warm temperatures (80-85 degrees). They will most likely rot if put out in the ground, or at best they will come up in mid June once the temperatures warm up. Soak them in warm water overnight and then put them in the largest peat pot you can find. Typically 4Ē is the largest you can get and really that is too small. I cut a coffee can in half and then tape it back together, use the plastic lid for the bottom and fill with potting soil. Put them someplace warm (a constant 85 degrees is the best) and within 4-7 days you will have pumpkin plants. Once you have plants they need to go outside in less the seven days. After that they start getting pot bound and pumpkins do not recover well from this. Typically my plants are set out within 2-3 days of breaking the surface.
#5. Pruning. In order to grow a big pumpkin you must be able to control growth of the vines and channel nutrients to the pumpkin. I typically grow in what is called a ďChristmas TreeĒ style growing only one pumpkin per plant (see diagram below). I let the main vine grow in  a straight line, secondary vines are allowed to grow to the edge of the patch (about 15í)and then they are terminated. All tertiary vines are aggressively destroyed. Pruning is something that needs to be done on a daily basis from the first of the season. As the vine grows dig a 4-6Ē trench in front of the growing tip and put the dirt on top of the vine that is already developed. This buries the vine several inches below the surface of the soil. Burying the vines is one of the most important parts of pruning. Roots will form at each node (thatís where the leaves come off the vine at) this will increase the ability of the plant to take up water and nutrients, and has a side effect of stabilizing the vines and leaves in the wind.
Seems like a good place to mention weeding. The best thing to use is a good old-fashioned hoe or my favorite is one of newer styles of ďwinged weederĒ. You donít want to be digging too deep close the plant. The root system of an Atlantic Giant is quite extensive and you will find roots 6-8 feet beyond the end of the vines. Use the roto-tiller with extreme caution. This is another job that is much easier if done a little every day rather then trying to start in July
#6. Fertilizing.  Yes, I do use Miracle Grow!  I donít use it all season long but at the start of the season I use it, in mid season I use a balanced foliar fertilizer (my favorite is Peters 20-20-20) and then late season I use a high potassium fertilizer. Typically I will use a foliar fertilizer on a weekly basis. I essentially follow the fertilizing plan outlined in How to Grow World Class Giant Pumpkins. I also use fish/seaweed emulsion on a weekly basis. Pre-planting fertilizing is done based on soil test results. Sorry no real secrets here. If a little is good a lot is not necessarily better.
#7. Watering. Actually not much here either, if it is dry then turn on the sprinklers. I have mine set up on an automatic timer so that it will water every third day. As a rule of thumb they say that pumpkins will need 1 inch of water every week. In our dry, arid climate I think this is probably too little water. I probably give about an inch every time I water. Use some common sense here. Again if a little is good a lot is not necessarily better. Too much water leads to problems with diseases and poor plant growth. female flowers produce the pumpkin. They are quite easy to tell apart as the female flower has a small pumpkin underneath it. The flower typically will open first thing in the morning. Once it opens you have a 4-6 hour window to pollinate it, after that it is too late. The bees might take care of it but do you really want to leave it to chance. If the bees do it for you, they are just as likely to pollinate it with the pollen from your banana squash or your neighbors (that lives Ĺ mile away) Hubbard squash.
Pick 2-4 male flowers that opened that morning. Rip off the petals of the male flower thus exposing the stamen and gently rub the middle part of the female flower (stigma) with the stamen. If you really want a guaranteed cross that you would be willing to grow the seeds from next year, then you must cover the flower before and after it has been pollinated. Otherwise, there is nothing to keep that bee covered with the Hubbard squash pollen out of the flower  and having a mixed pollination. Some seeds may pollinated with pumpkin pollen and others with Hubbard squash pollen, and still others with Banana squash pollen. I typically take a piece of yarn and tie it loosely around the petal of the female flower, thus keeping unwanted visitors out of the flower.
#8B. Cull to one pumpkin. This can a be an emotional challenge. Several growers have shown up to the weighoff with 15 pumpkins from one plant. Unfortunately none of those pumpkins are really big. There has been too much competition for nutrients and you end up with a bunch of mediocre pumpkins. If you want to grow one bigger then mine you will have to do this. Typically I set several fruit and then measure them on a regular basis for about 10-20 days and see which one is growing the best. All fruit do not grow equally. Other things to consider besides the rate of growth are the shape of the fruit, the length of the stem and whether it is on a main vine. Main vine fruits do better then fruit on secondary vines. I did grow a 709 on a secondary vine this last season simply because my main vine fruit was much slower growing (also pollinated later) so I culled it. I have grown two per plant before but this is on a plant that is pruned with in double Christmas tree and the plant takes nearly 1300 square feet.
#8C. Eliminate stem stress. What the heck is stem stress? As a pumpkin approaches 3-400 pounds it begins to get large enough that the shoulders on the pumpkin put pressure on the vine. This pressure can literally rip the fruit from the vine. It can also cause the pumpkin to have a weird shape. When you see a female blossom beginning to form, begin training a 90 degree bend in the vine with the blossom positioned at the outside curve (see diagram below). Then about 3 feet beyond the blossom straighten the vine out so that it is headed in its original direction. This positions the vine away from the shoulders of the fruit and will help save the day in the end.
As the pumpkin begins to grow it will lift the vine up. At this point it become necessary to cut the tap roots 2-3 nodes in either direction thus decreasing the downward pressure that the vine produces on the stem.
#8D. Fruit shading. The fruit can and will get sunburned. This can cause hardening of the skin and limits expansion and growth of the pumpkin. It can also lead to significant cracking and scarring of the pumpkin as well. Typically growing giant pumpkins is not a beauty contest but there is no reason to intentionally challenge them. I cover the pumpkin with a tarp supported on a frame of PVC pipe. This keeps the sun off and keeps the fruit dry.
#9. Late Season Protection. This is one of the most difficult tasks. No it is not necessary but if you really want a giant it is a must. I can get 200 pounds of growth in September but not if it freezes on September 1st (typical for Idaho). I donít cover each plant, just that of my biggest pumpkin. By covering the entire plant and adding supplemental heat you can easily keep the plant alive and thus keep the pumpkin growing until it is time to be picked for the weigh-off. I have constructed a frame and draped it with plastic to cover the plant. If you really want some information give me a call. It will most likely require so ingenuity to get this job done.
#10. Hard Work. I really donít know how much time it takes, but it is a lot. Ten hours a week is probably a safe estimate. The busiest seasons are early spring getting the patch ready. Late June and early July is pollination time as Iím getting up at 5:30  to pollinate the pumpkins and then burying the vines in the heat of the day when the vines are more pliable, and less likely to break. Believe it or not October is also a very busy season getting the patch ready for winter, hauling manure, getting soil samples, collecting leaves and chopping hay. If youíre afraid of some nice physical labor growing pumpkins is probably not for you.
#11. Education. This is a nice little primer on growing pumpkins but it is not meant to be all-inclusive. Read as much as you can, ask questions, and visit other growers. Some suggestions on where to turn. How to Grow World Class Giant Pumpkins Volumes 1,2 and 3, are invaluable resources with a wealth of information. They are the best-written resources out there. They can be ordered through Amazon.com. Numerous online resources exist, two of the best are www.Bigpumpkins.com and www.hort.net/lists//pumpkins. Give these two site a try on cold winter night and see what they have to offer. If you have questions feel free to call me or to drop me an email. I love to talk pumpkins.
#12.  Good weather.  Sorry, I do not have a weather control stationÖ..yet? If you really want to have better pumpkin weather move someplace with more mild tempuratures. I would suggest Washington, Oregon, or New Hampshire (this is where all the big pumpkins come from). Short of that you are on your own.


Brian W. Christensen MD, FACS
20 Madison Professional Park
Rexburg, Idaho 83440
Home phone 359-2954
Email Bchris1335@aol.com

The Seventh Annual Eastern Idaho Pumpkin Pickiní Party  will be held on Saturday, September 30th, 2006.This will most likely be at my house again. I keep toying with the idea of getting corporate sponsers and going big time, but I'm afraid that will take some of the fun out of it. I will try to notify everyone who received seeds. If you donít hear from me give me a call.