I like leropetelum (sp) but they might not be dense enough for what you need.

If it was me I would pick bamboo.....specifically multiplex either in the normal green stemmed form or Alphonse Karr which has very pretty yellow culms (stems). The bamboo can be hedged at any height or left to it's own will hit in your case I am guessing 20 feet but as I said can be topped at any height. If you take the multiplex and space them 4 feet apart they will quickly hide your view and in a couple years form an absolute impenetrable wall a cat won't get through. It is hardy to 10 degrees, grows fast and once established needs no extra water.

I would water and fertilize it the first couple years as that will greatly speed up the view blocking process. The larger the plants you buy the faster they will block the view. The picture below is of my property. This is the normal green type multiplex. This row of plants were single culms (stems) removed from the mother plant last March. The picture was taken last summer so that is what the single culm did in growth in just 5 months. It is planted along a property line, 1000 feet of it or so and has been a multiyear project. It is to block my view of the neighbors who I love but privacy is always a nice thing. So you can just imagine what a multiculmed established pot will do with proper care.

This picture shows what 3 year old cuttings become. Can you see what is behind it? NOPE. This is a clumping bamboo so will not escape, it simply enlarges the circle it grows in every year.

You can buy large pots of the bambusa multiplex or small. Some places will sell you entire mature bushes for $100 each for an instant barrier or you can go small pots with 2-3 culms in them for perhaps $10 a pot. All depends on your budget and wallet.

Surinam cherry. They are evergreen, dense, and healthy. Buddelia will not work for want you want to do, but is worth a try in your flower garden.

Bamboo is cool but it might be a challenge if you wanted to keep it groomed to a formal look.

If I wanted a dense hedge I would probably go with arborvitae. It's bullet proof and excellent smoking wood for the grill. I don't know if it's related to the Cypress family though.

Captturbo,

The multiplex is actually extremely easy to groom to a formal type shape. On mature clumps they shoot over a short period of time so a once a year trim is all they need. Once a culm is topped it never grows again so all you have to trim yearly is the new culms that come up from the ground.

If you go to this link it is a favorite restaurant of ours in Ocala, it is a Brazilian steak house. Zoom in and The bright green line in the picture right next to the A is a row of formal shaped multiplex that is perhaps 5 years in ground and was planted at 5 feet on center. If you mess with the street view feature you can actually get a good look at it.

Here is a link that might be useful: formal bamboo

I messed with it a bit and when (I think) I finally got the picture tuned in to what I wanted to look at and magnified it didn't look like bamboo to me. Maybe I'm even worse then I think at working that google thing. Maybe I was looking at something in Nebraska? Oh and at this hour I'm brinking some deer. LOL

Lol:) I know in the pic it does not look like bamboo but it is. It is very pretty.

I suggest Jamaican Caper (Capparis cynophallophora). I've seen it as a hedge and it is very attractive.

have three types of cold hardy bamboo here, love it....but it is dirty with leaf drop. continually cleaning up around it. ligustrum would be my pic!

Take a look at Walter's Viburnum.
It is a Florida native.
The leaves will remind you of boxwood.
" Walter viburnum, in the opinion of some nursery growers, is the very best viburnum for use in central and south Florida. "
Can grow to 25 feet tall and takes kindly to trimming or shearing.
Also comes in a dwarf form.
Look on Google Images for photos.

How about viburnum- http://www.google.com/search?q=viburnum+hedge&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a

or podocarpus http://www.google.com/search?q=podocarpus+hedge&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a

or Indian Hawthorne http://www.google.com/images?q=indian+hawthorne+hedge&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&um=1&ie=UTF-8&source=og&sa=N&hl=en&tab=wi&biw=1016&bih=563

Lori

Clumping bamboo is our choice too. We like our neighbors on either side but one is elderly and we are thinking ahead to who lives there next.

We have about 8 different kinds of bamboo but the one that we have lots of planted as a privacy hedge is Seabreeze bamboo (Bambusa malingensis) because it has density and is leafy from bottom to top.

I also planted some elderberry which does a good job but it's more invasive. It grows fast though and could be used in between plants until the bamboo grows thick enough. Some native plant nurseries sell it.