I grow a different holly (ilex meserveae) and it does fine. The link below says ilex opaca is hardy to zone 5, so it should be okay, but I don't recall seeing any large holly trees around here.

You could do a post on the trees forum and ask about how it would behave in zone 5. The tree forum has a lot of experienced growers.

See link for more information.

Here is a link that might be useful: american holly

Yes, there are Ilex opaca growing in protected areas of Perinton. The last time I saw them they were doing well. If your RIT landscape provides a quiet, sheltered spot, give it a try. Just remember not to plant one close to a building where the westerly bright sun in winter radiates from the siding/brick creating a heat pocket. This type of situation kills hollies.

Hi,
I just found this forum as I am usually on Aroids or Trees, looks like I will be here as well!
American Hollies do grow in WNY and reach a decent size. I live in Hamburg and often walk around ECC south campus near Ralph Wilsom stadium in Orchard Park. In the courtyard like area are some hollies about 15 feet tall and they are protected from the wind that are brutal in this area. I have collected seed about 3 years ago and had one germinate.I know they are slow to germinate! My rationale is they are this tough, then the seedling hopefully will have this trait! I just collected more seed last Tuesday and will sow them in sunken pots so I know where I planted them!
I know they do not like wind so they appear to have grown good despite minimal care since they were planted.

HTH - Gerry