Buy the 2015 Old Farmer's Almanac!
Some Pumpkin Varieties doSome Pumpkin Varieties do have very dark green skin, they are suppose to be that way. The flesh inside will very likely be orange. It sound to me that your pumpkin is ready to harvest. Enjoy, try Pumpkin Soup with a little bit of Laksa Paste &Coconut Cream added, it's yummy

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