Pollination..Pollination..Pollination The end of June and through the first 10 or so days of July are the 'golden window' for giant pumpkins. July 4th is not only the birth of our nation but also prime time for the begining of our giant pumpkin. Your attention has been at directing the main vine to orient the female flower on the outside of the curve all in anticipation of pollination. Don't trust all your hard preparation to the bees, be proactive and be sure the pollen gets from the male flower to the female flower when she is open in the morning. Remember, the female is only receptive on the morning she opens. Cover the flowers the evening befor they will open. Refer to the mid to late June pictures to help identify when they will open. Its very easy once you see it happen. After you have completed the pollination re-cover the female to keep those pollen theives out!! Remember to take notes for yourself so you will have them for next year. You will know who the parents are of your prize and the time and conditions when it was pollinated. If your pollination is incomplete the little pumpkin will fail to develop correctly or abort. Even if you complete the pollination correctly there are other obsticles to success. Weather is the primary problem. If its raining during pollination and the inner parts of the female get wet it will most likely fail so keep her dry. The more common issue is high temperature. If it is to hot on the day of pollination it will fail. At the very least you can provide some shade over the little female on pollination day and for a few days after. If its vey hot or the sun is very strong, shade alone may not be enough. In these cases you will need to do additional things to cool the enviroment near the female. Try covering her with a styrofoam cooler with bags of ice inside. Near but not touching the flower.
A bed to rest on or what to put under your pumpkin ...You will need to create a separation between your pumpkin and the soil to prevent diseases. If you use sand and/or landscape fabric the sand will help to support the pumpkin as it grows.
Continue pest managment ...It's important to continue the pest management you began in June. Watch for our 3 main pest, cucumber beatles, squash vine bores and squash bugs, also known as stink bugs.
Pruning and vine managament ... Use babboo stakes or "U" shaped pieces of plastic coat hangers to position and direct the vines where you need them to grow. Only move the main or secondary vines during the heat of the day so your plant will have the typical xmas tree shape. Any vine that originated from a secondary vine should be removed promptly. Soon your vines will reach the maximum length of 10 to 12 feet at which point you should terminate their growth by cutting off the growing tip. After a couple days you can safely bury the tip.
Watering and misting ....With the days getting hotter it's important to be sure your plant gets enough water. On very hot days with strong sun the plant will not be able to keep up with transpiration and the leaves will wilt. Daytime misting will cool the leaves enough to keep them up and avoid heat damage.
Disease and fungicides.....Hot days and warm nights are great for the plant growth but along with that comes high humidity. These conditions promote powdery mildew. Prevention is the only way to deal with it. Daconil is one of the fungicides that is effective for it. If you must use organic controls for powdery mildew then look at Matt's excellent research on the use of milk and its' effectiveness.