What are you conditions? Wet, dry? Shady, sunny? etc..

Hi Sandra,
this may be a bit of a trek from Lagrangeville,
it is for me too, but I find it worth the trip
once or twice in a season.
Friendly, unassuming place with great selections
of native plants, including water plants.
Here's the url of their web site:

http://www.catskillnativenursery.com/index.html

On May 1 at WCC they are having a Native Plant Sale. I have never been able to make it .

Here is a link that might be useful: WCC Native Plant Center

Thanks to all for the information.
Sandra

Firstly, what is your deer situation? Deer have eliminated a lot of our native plants and are going to destroy almost everything you plant unless you stick to a few things they hate - and that doesn't always prevent deer damage. The ecology here has changed drastically since deer have moved in and a lot of our choicest natives have been grazed out of existence. If you are not going to protect against deer, you are fighting a losing battle. I found that out the hard way when I tried to plant our native wild azalea - it never had a chance.

Update: thanks for nursery advice:

I attended the WCC native plant sale but most of the perennials were gone during a pre-sale.

I also went to the Catskill Native Nursery and they had a diverse selection of perennials, trees and shrubs.
I was intrigued about American wisteria (which they are getting in soon) so I have to think where it might go on my property. I have two acres and just about all conditions: shade, part sun, and all day sun. The only condition that is usually absent for long periods is wet.