How to Grow Giant Pumpkins
- Seed selection - don't be fussy that first year. Just get a few seeds from a reliable grower or two. There are many good Atlantic Giant crosses out there for the asking in the Giant Pumpkin community.
- Outside, soon as the soil can be worked, have the soil in your garden tested. Ph needs to be 6.7 to 7.0. Colorado soils tend to be alkaline (7.5+) keep the nitrogen on the low side but the additions of kelp meal, humic acid, soil soups, and aged organic matter helps them grow big. Adjust your soil according to the needs from the soil test. Do not over apply. Use Gypsum for increasing Calcium levels and Elemental Sulphur to lower the Ph.
- Deep till your patch once after adding all amendments. Dig holes where your plants will be placed, cover area with a mini hut or greenhouse type closure so the soil and hole will warm up (at least one week before expected planting time) add Mycorrizah fungi and/or root shield into hole and also in trench when vine burying all season long. Allow a minimum of 400 square ft. (20' X 20') per plant. Many make the mistake of cramming too many plants into a small area. One can grow in a smaller area, but will also have a smaller result
- Practice your seed starting skills by germinating a couple seeds before it really counts. Just sand the sides and crown of seed lightly. Wet a 4 to 5 inch peat pot and fill with moist seed starter mix (not potting soil), press sanded seed - tip first down into the seed starter. Then cover with 1/4 inch of starter mix. Do NOT over water as this will cause seeds to rot in the ground. One should not be able to squeeze but a few drops of water at all from the starter mix, when properly moist. Mark or tag your pots so you know what seed it contains. Popsicle sticks work well for this.
- Germinate your seeds by placing them in 4” or 5” peat pots in a germination chamber that will give you a constant 85 to 90 degrees of heat. Use a germination mat or another easy method is to get a large plastic cooler, Drill a few air holes around the sides, attach a metal tray or heavy mesh screen across the middle of cooler, then string two 60 watt bulbs into the bottom of cooler, to keep the cooler warm. Use a clear Plexiglas top to slide as needed for a constant heat adjustment between 85 and 90 degrees. Keep pots and seed starter moist not excessively wet. Be careful not to overheat your plants. Adjust as necessary.
- Seeds will germinate in 4 to 5 days. After seed leaves are fully exposed gently pull off seed shell (BE very careful) , sometimes spraying lightly with water on the shell helps loosen and soften the shell for removal, be careful not to damage the young first leaves called cotyledons.
- Place seedling under a grow light or in a sunny location. Place in cool garage at night (harden off), then partial sun in the day time until the first true leaf (some call it the third leaf) shows up. This usually happens only a couple days after the shell has been removed. Be careful the wind doesn't snap the main stem, if you place them outside.
- Plant seedling in the ground, with first true leaf dropping in the opposite direction you want the main to go or toward the first two true leaves and the plant will tend to drop and vine in that direction. (True leaves are not the first leaves to appear but after the round cottels appear and have a pointed end to them).
- Keep plant covered on cold nights with a Styrofoam cooler over the seedling. Use a heating cable in the ground if you wish, some also use a small light to keep the hut/greenhouse warm. -------this is very important to the plants health. Colorado nights in May can be cool. Average last frost is the 15th of May. Watch your weather reports.
- Don't cook your plants in the daytime heat, but keep them covered at night temp permitting, on hot days, better to leave huts open a bit rather than burn them up.
- Fertilize with mild (1/2) solution of kelp (Seaweed) and fish (5-1-1) water soluble or a manure tea with half the amount of water soluble kelp/fish. Grow your plants organically for best results.
- Colorado Winds. Keep a four foot or higher temporary wind fence up around young plants once greenhouses are removed. Keep fence up until main and side roots are buried and anchored well. One can use plastic coat hangers cut in half or small dowels to help hold down the vine, until the roots grow to hold down the vine.
- Once the plant starts to throw a main vine it is very critical that you do not use any commercial high nitrogen fertilizers. The nitrogen makes the young main very rigid and easy to snap. We build a small hill under the main so as to let it down gently by scraping out a little soil every day until the main is all the way on the ground. If you force it too much, or try and work the plant too early in the AM, before the plant warms up, you will snap it every time.
- Train the main vine to run straight out from the base. For example, if the main is running due south, then each side needs to be trained to run directly east on one side of main and west on the other.
- Each side vine end should be a minimum of 10-12 ft from main before dead ending vine growth (cutting the end and burying into the dirt). To grow something truly special you need a minimum of 13 to 14 sets of sides (secondaries) before you pollinate a fruit. Any fruit before that should be snipped off. Depends on size of your patch.
- Remove all tertiaries, or third vines from the secondaries. After your first fruit or two are set, remove all remaining baby pumpkins. To grow a big one, one wants only one or two fruit per plant with the prime fruit on a main vine if possible, about 12-14 ft out.
- Find out what pests and diseases are common in your area and take steps to protect your plant. If not your season could be over by the middle of August.
- Never water at night, if so make sure leaves are dry before nightfall. Spray pesticides very early in the AM or late PM, NEVER, during heat of the day. Keep soil moist but not flooded. Water over the top as little as possible as splashing also spreads disease.
- Buy some books like The Don Langevin collection, –How to Grow Giant Pumpkins” 1,2,3 especially books # 2 and 3. READ them several times. There is a lot of information available for growing giant vegetables....
How to DVD's are available at: http://www.hollandsgiants.com/video.html
- Nuzzle up with a good grower in your area. Nothing beats a first hand look at what a good grower is doing. We share all information, Ask questions and Visit our facebook page:https://www.facebook.com/RMGVG and www.BigPumpkins.com for lots of helpful information from growers. Advanced information is
available for those growers attempting to break the Colorado State
Record. Good Luck!
- Have fun with your growing. Anything is possible.... If you can
dream.... don't give up on that dream..... You will be rewarded. Grow