Went to buy a barberry shrub at the garden shop and was told they are forbidden in New York state. Can you help me out?
Japanese Barberry specifically, is on the list of invasive plants that cannot be sold or planted in the state of New York. This is due to new legislation passed by the New York State Department of Conservation. The complete list of prohibited plants can be found on the New York State Department of Environmental Conservation's site: http://www.dec.ny.gov/regulations/93848.html
There are other varieties of Barberry, however, which are NOT invasive prohibited species, and this article may help you choose one of those: https://www.gardeningknowhow.com/ornamental/shrubs/barberry/barberry-shrub-care-tips.htm