Please turn on sound. NOTE: click on download, then click on video picture in the very bottom, far left corner of your computer to see VIDEO. (Took me a while to figure this out, I'm elderly, graduated in 1966, did not have computers in school at that time, Book Learnin' Only).
Enjoy.

Also, Jana, sorry you did not have Pine Siskins or few American Goldfinches in Washington this year.

Feeding Thistle seed & Shelled Sunflower seeds will encourage these birds to visit.

Thanks
As I said I believe a nest in in the area since I have seen one in my yard 3 or 4 times and several times I have seen one flying with the local mockers or crows going at it. A couple times I have seen one take off from the large tree in the yard on the south side of the block and when chased by the mockers and crows they always go west down the center of the block there are a couple of undeveloped areas that way and one large complex with a park and man made lake. About a mile or less straight line to the foothills.
I have the biggest bird feeder group on the block so my yard would be Snack R Us for them, but I have never seen one get anything or found signs of a kill, except one sitting on the power pole eating a lizard. And the birds at the feeders were ignoring that one.

Here in So Cal the Home Depot and Lowe's chains sell potted milkweed. Other places also and most nurseries. There are lots of online sites that ship plants and seeds. Some sites have the resources to help you pick the species that are native to your area.
Just google "milkweed seeds" or Milkweed in Pennsylvania, a lot of other sites will come up.

Here is one of the national Monarch groups and they provide seed and info on which ones for your area:
http://www.livemonarch.com/free-milkweed-seeds.htm
and another good one, the National Wildlife Federation:
http://blog.nwf.org/2015/02/twelve-native-milkweeds-for-monarchs/


Here are a couple that are specific to PA:
http://statebystategardening.com/state.php/pa/newsletter-stories/help_to_bring_back_the_milkweed/
http://www.growmilkweedplants.com/pennsylvania-native-milkweed.html

They grow well in pots etc. One clue from landscapers is if you don't like the rather spindly look a lot of them have you put them in the back and plant flowers or other things as tall or taller in front of them.