Fold the rectangle of fabric in half with the right side facing inwards and stitch down the open short ends to secure in place leaving about a 1/4 inch seam allowance (you can just about see the stitches on the right hand side of the fabric).
Secondly, with strong doubled thread sew around one of the open ends with running stitch and rouche/cinch fabric closed as you sew along. When you get to the end stitch to secure and close any gap. I had quite a large gap as the fabric I chose was a thick velvet and didn't rouche that well but a few stitches across the bottom held the gap closed.
Now turn the fabric pouch inside out so the right side of your fabric is now showing
Then thread a long knitter's needle with embroidery thread or wool. Push the needle through the bottom of the pumpkin and out through the top wrapping the embroidery thread around pumpkin at quarter intervals, keep pulling through the core several times, to add ridges around your pumpkin.
I used embroidery thread for this but later changed it to a thicker wool which you can see much better, it is also stronger. Finally for the stalk, cut out 2 stalk shaped piece of felt or fabric. Sew the two pieces together with the right sides facing. Turn inside out so right side is facing and stuff with wadding. Stitch to the top of the pumpkin to secure.
When I was threading the wool through the core I left some longer tail pieces to look like tendrils.
Have fun making these pumpkins and mix them in with real ones to make a really effective halloween display. Send me photos of how yours come out!