Are you looking for plants that bloom in autumn in PA? Right now, this is what we have in bloom in our PA garden and yard:

Non-U.S. native plants:
Hardy Mums: So many colors available nowadays. Great for fall garden color.

Sedum 'Autumn Joy' (Sedum telephium): Lovely blooms in a subtle pink.

Marigolds: Still in bloom at this time of year for us.

U.S. Native plants:
Asters: Aromatic aster, Heath aster, Smooth aster, etc. Especially nice is Symphyotrichum oblongifolium/Aster oblongifolius 'October Skies', which has very vivid lavender-colored blooms. I have to remember to take a picture of this one to post.

Goldenrod: We have Late goldenrod blooming right now. Some find this plant weedy looking, but it depends on how formal or informal your garden is. It looks great in our wildflower/natural style garden.

I had this posted in another forum. It was taken a week ago, but it still looks great even after last night's frost. Sheffield and Mary Stoker mums, Autumn Joy sedum, euphorbia Chocolate, and the remains of various asters.

Here is a link that might be useful: {{gwi:280105}}

Sorry, the white flower is eupatorium Chocolate not euphorbia.

Here is a link that might be useful: October Garden Link in Perennial Forum

I love my Itea 'Little Joe'. I just bought it this past summer and the fall color is brilliant. It also have fragrant white flower shoots in the summer. It's a real winner.

I agree that 'Autumn Joy' sedum is a great addition and easy to find.

My marigolds are still putting on quite a show.

Another great plant that has quickly become a favorite (if not THE favorite) is my Acapulco Salmon and Pink Agastache. I LOVE THIS PLANT. It smells like lemon Pledge when you walk by it. Bees love it. I planted mine late last fall. It bloomed non-stop from Spring until...well, it's still HEAVILY blooming. I wish I had an entire garden of them. Seriously. They're marvelous.

An annual that is doing beautifully is 'Strawberry Fields' gomphrena. They look like red cotton balls. They are stunning in bouquets and were easy to start from seed. Seed is very easy to find.

Hosta and heuchera are great for shade gardens. I have many different varieties of those. I've posted quite a few pictures and descriptions on my blog. I'll post the link below. They are great perennials for a spot that gets some shade.

Here is a link that might be useful: Kim's Pennsylvania Vegetable and Flower Garden

I incorrectly listed the name of the sweetspire. It should have said the following:
Itea virginica 'LITTLE HENRY'

Other info: ('Sprich')- 2Âx3Â, Z 5-9, full sun-full shade

I have this gem of an orchid in bloom right now & expect it to be still blooming in Nov! Highly recommend it.
http://www.brentandbeckysbulbs.com/summer/productview/?sku=89-56
YouÂll have to wait until spring to order it DonÂt forget :)

I am very new to gardening and have a plant that is lush and green all year but to doesn't have flower buds until late summer and they only start to bloom in October. It is deep purple flower and I am telling you it only opens in the day and closes up at night. It closed up around 8pm tonight. The bud heads/blooms look twisted when closed. it is beautiful. I have a picture but joined this site tonight and don't know how to load a picture.