The leaves on the pumpkins will go crispy and shrink back after the first frost revealing the swollen fruits beneath, and you should be able to tell that they are ripe because they will have a nice orange skin. However not all pumpkins need to be 'all the way' orange to be ripe, and some pumpkins varieties will still be completely green such as 'Fairy tale' and the old Italian favourite 'Marina Di Chioggia'.
When you are ready to harvest a pumpkin, there are three checks that you can make that will tell whether it is ripe or not. The first is to give it a good thump or a slap. If the pumpkin sounds hollow, that the pumpkin is ripe and ready to be picked.
The second way is to check the skin as it should be hard once the pumpkin is ripe. Using your thumbnail (presuming that you have one) gently try to puncture the pumpkinís skin. If the skin dents but does not puncture then the pumpkin is ready to pick. The third way is to check the stem leading from the pumpkin. When it starts to turn hard, the pumpkin is again, ready for picking.
One of the first to ripen is the popular 'Baby Bear', one of the microwave varieties with just enough sweet potato-like flesh for a meal for two. Other varieties such as 'Uchiki' will still be ripening and you can tell this as the stem will be bright green. When it comes to harvesting unripe pumpkins it's always important to leave a few inches either side of the stalk. Thatís because you want the stalk to dry off slowly and naturally so that it seals between the stalk and the pumpkin flesh. If itís not perfectly sealed then rots can get in and your crops won't keep. If done properly your crops should last well providing for good meals up until February.
Curing pumpkins is all about getting the rinds to harden, and you can do this by bringing them into a greenhouse or by sitting them by a sunny window in your kitchen. If you can leave them there for a fortnight or so you will notice that the skins will colour up and the flesh inside will sweeten as the starches inside turns to sugars and improve the flavours no end. After the fortnight, turn them upside-down so that the bases can colour up as well. Then they will be ready to be kept in a frost free place for several months where they will still remain edible.