[vanessa.xx]

I have a pumpkin growing in my back garden and it has now turned completely orange, my question is when should I harvest it? I'm not in any great hurry will it rot if I leave it on the vine still? Is there any benefit to leaving vs picking? And can I store it in my shed and how long will it keep I know to leave a long stalk on it

[allotmentann]

As far as I am aware, and I am not a great pumpkin expert, they will last fine on the vine until the first frosts. I guess, leaving it on the vine as long as possible, will mean that it keeps growing and ripening. I imagine that once picked, however carefully stored, the decaying process begins. Pumpkins can keep for months, but it is difficult to say how long any one pumpkin will keep, that depends on many things. For example, any slight blemishes or scratches on the skin tend to let the rot begin, so a blemished pumpkin will probably not store as long as an unblemished one.
The variety too probably also affects how long it will store. I still have one or two small Hooligan pumpkins from last autumn. The flesh also tends to dry out as they get old. The only thing you can do once harvested is to check on them regularly to be sure you use them before they go off. 

[simonwatson]

Once it's orange, it's stopped growing so time to move it to storage. They store best when kept at room temp or just below. No darkness is required. I keep mine on a windowsill in the kitchen. They are a tropical plant, so just like bananas, storing them at low temp actually makes them go off faster.

[mumofstig]

Harvesting and storage

Leave the fruit on the plant for as long as possible to mature and ripen. When the stem cracks and the skin is very tough, the fruit is ready to be picked.
Cut fruit off with a long stalk before the first frost. Pumpkins can be stored between four to six months.
Expose the pumpkin to sunlight outside for ten days or keep indoors at 27-32ºC (81-90ºF) for four days to harden.
Keep your pumpkin stored in a well-ventilated place at about 10ºC degrees (50ºF).

http://www.bbc.co.uk/gardening/basics/techniques/growfruitandveg_growingpumpkins1.shtml

[compostqueen]

I keep mine in the conservatory all winter with the windows on inch lock and the heating on minimum.   My husband cranks up the heat and I go right after him and turn it back down again. It's a game 

[vanessa.xx]

Thank you everyone and especially mum I will leave it until the stem cracks