- Seeds should be started inside on or about the last week of April, depending on the weather. Use a 4" pot or larger, filled about ¾ full of potting soil, to start your seed. Quart size ice cream containers make great starting pots. Invert the well cleaned container upside down so the cover is on the bottom. Cut the original bottom out of the container and use as the top of your makeshift pot. Be sure to punch holes in the bottom or your pot to allow excess water to drain. When your ready to set your plant in the ground, remove the bottom cover of the container, the top of the original ice cream container, and your seedling will slide out into the prepared planting spot while not disturbing the roots. Atlantic Giants can fill a 4" peat pot with root in 7 days so if the weather isn’t cooperating and your plants may be inside for more than a week, go with a bigger pot to start.
There are several methods to start your seed. When growing Atlantic Giants, it isn’t as easy as simply placing the seed from the envelope directly into the pot without any preparation. If you want to improve the speed and reliability of germination, especially if you are fortunate enough to have obtained a ‘hot’ seed, there are a couple things you can do prior to placing the seed in the pot that will do much toward increasing your odds that it will germinate.
First, very lightly file the edges of your seed with a nail file or fine sandpaper so that a very small amount of the seed coat edge is sanded away. Stay away from the pointed end. You should just start to see a color difference along the edge if done correctly. This will aid moisture in penetrating the seed coat.
Next, soak your seed for up to 8 hours before planting in warm water. This will give your seed a jump start in getting moisture into the seed. Some growers prefer to soak in a mix of water and seaweed emulsion or hydrogen peroxide and water. The hydrogen peroxide produces oxygen in the solution that is believed to be a benefit in germination. After soaking the seed, wet a paper towel and squeeze most but not all of the water out. Carefully wrap the seed in several folds of the paper towel and place it in a zip-lock bag, leaving just a bit of air inside. The seed then needs to be kept between 85 and 90 degrees for optimum conditions. There are several ways to achieve this, depending on how much effort you want to put in to getting the seed to sprout.
The warmer you keep your planted seed, the faster and healthier your seed will sprout. The easiest way is to simply place the zip-lock bag on a warm surface such as the top of a refrigerator or a computer monitor. This method is not a controlled environment and temperature variants may be detrimental to your effort. Another method is to create a type of seed incubator with a big cooler and a bottle of hot water placed inside, changed 2-3 times a day. The most intensive method is to build a germination box like the one in the How-To section. A germ box gives the most controlled environment in which to germinate your seeds. Your seeds will stay nice and warm in a fairly constant 85 degrees thereby speeding up the process with more consistent results.
In 3-5 days, depending on the temperature and preparation, your seed should begin to sprout with a small root protruding from the pointed end. At this time you should have your pot and growing medium ready to receive the newly sprouted seed. Poke a hole in the growing medium and carefully place the seed in the hole, insuring that the root is not pressed into the medium and that the top of the seed is about ½" below the surface. Gently pack the medium around the seed with a fork until the hole is filled in to the surface of the medium. Now place the pot in either a warm sunny spot or back in your germination box until the seedling breaks ground. Try to maintain the 85 degree temperature day and night.
After your seedling breaks ground, if your using a germination box, remove the pot and place in a sunny window. A fluorescent light placed a few inches above the pot will help your seedling ‘green-up’ faster and prevent the stem from getting ‘leggy’. Short and stumpy is better than tall and lanky.
Many times the seedling will have some difficulty in shedding the seed coat. You can very carefully slide this seed coat off the seed leaves if it doesn’t come off by itself a couple days after breaking ground but use extreme caution in doing so.
Continue to keep the soil moist but not wet, pumpkins don’t like wet feet. Once your plant is about 5 days old you should notice the first true leaf forming between the seed leaves. When this leaf grows to about 2" across it and the weather is cooperating, your ready to set your seedling in the ground inside the coldframe you erected earlier. Place the seedling in the ground up to the bottoms of the seed leaves, insuring that the first true leaf, the one in the middle, is facing opposite the way you want your main vine to run. This is not to say that your plant may not cooperate and begin to vine the wrong way, but 9 times out of 10 it works.