Does any one know how long it takes to grow a balsam fir from seed to around 7 foot.

It depends where its planted, and how well you take care of it. From seed...I would guess up to 15 years. You could cut that in half I bet if you dig one up when its about 2 ft. They aren't grown from seed too often. Your better off buy/digging up seedlings. If balsam fir grows naturally in your area, I'd think about digging one up. Ask the land owners permission of course. If they don't grow in your area, you should probably grow something else.

I recently watched an episode of this old house. They went out to a Christmas tree farm. Most of the trees were anywhere from 10-15 years old before they were tall enough to be cut for Christmas trees. It also took yearly pruning to get the trees to grow correctly. I would begin with some rooted cuttings before I started with seed. I am assuming you can go out and take some hardwood cuttings now and use some root stimulator, then place in some coarse sand.The germination process might be intensive or have low rates of success.