starlightfarm, I'm in a similar situation with my property as well. I'm building the main part of my hedge with white pines. I'm not sure about the toxic properties of Pine but a nice evergreen like pine or cedar may be a good choice for you. On mine, I'm going to come back in the next row after the pine with some holly. And have some strategic areas that I've got a mix of some other plants to help with privacy in particular areas. Check out the State Forestry sales, you can get some good deals on trees from them when you are looking for quantity. My experience with SC Forestry has been excellent! Good luck!!

Starlightfarm,
Please research online the wax myrtle, myrica cerifera.
It is recomended as an ideal screening tree or hedge and it is beneficial for the birds in your community.
It is very fast growing, evergreen, non poisionous, feeds a multitude of birds in your area over the winter and it is beautiful (I just planted 2).
Just research online, they sell them anywhere shrubs are sold and they are inexpensive.
I planted just 2, and they have grown at least 18 inches in the past month alone, and they are bushier. Very fast growth rate.
I am going to buy more of the them.
Their foilage smells terrific also.
Good Luck.

nannerbelle.... evergreens are a definite consideration of ours, as goats are VERY fond of them! We have pygmys, so the trees would stay pruned about 4 ft up year round! Thanks for the recommendation to check out the State Forestry Sales, I would have never thought about that.

butterfly... I'm off to surf the web to check out wax myrtles. Sounds very interesting!

Thanks for the suggestions.

You might consider some of the tall ornamental grasses that grow 5-7 feet high in short order. My Miscanthus 'Cosmopolitan' was probably 6 feet last year (2nd year for it). I should have divided it this year as it already has that donut space in the middle. I don't have Panicum, but I think it's okay to plant. I've been pulling out all of the Love Grass in my garden because it is too aggressive (I find too many seedlings, even in the gravel driveway).

Buddleia 'Royal Red' is a fast-grower, but there will be the springtime cut back with both buddleia and grasses where they won't screen -- at least you can do the maintenance at the same time.

A Curly Willow is another straight up, fast grower. May be short-lived. Mine are away from any underground pipes, but some say they don't present the same problem as roots of other willows.

Cryptomeria is another favorite fast-growing screen tree in my garden. I started with rather large trees, but they have probably grown 4-5 feet since planted in fall 2005.

Oakleaf hollies (maybe too prickly for riding arena area) haven't been eaten by the deer like Nellie Stevens and some other varieties.

Cameron