Keep the pumpkin cool and dry,
BUT NOT COLD,
they shouldn`t freeze.
They also shouldn`t be leaning against anything or pressed against each other.
Basement or garage as long as it doesn`t go below zero.
If you have a rack or plant stand,
you can put a towel on it and keep the pumpkin on it.
DO NOT FREEZE.
Every one keeps telling people to freeze their pumpkins but that will turn them to mush.
If you`ve already carved it (well,
I once carved a pumpkin a few days before halloween,
like 2 days,
but there was a dent in the pumpkin and it started to rot where the dent was.
Mold spread really fast.
I had to scrape the mold off,
spray the inside and carved area with a bleach and water blend,
let dry and slather it with petroleum Jelly.
Petroleum jelly keeps it moist but actually causes it to create mold and shrivel faster so not a good idea. Stick to water bleach combo and refrigeration. Also choose a pumpkin that is heavy compared to others of its same size. The thicker the walls are, the longer they last.. Buy your pumpkinnn 1 week prior to halloween make sure its is nice and firm, and heavy. Keep it refrigerated until you plan to carve it. (it is a vegetable remeber) Even after carving which I wait to day no more than 5 days prior but usually within 3 days prior to halloween make a water bleach solution and spray the pumpkin with it inside and out. Then dry the inside with a towel. after this put it in hte refridgerator and keep it there until Halooween night. It will look like it did the day you carved it. Especially if you do a lot of intricate designs like I do.