If there was one shrub I would urge you to remove from your landscape immediately, it would be this one. Japanese barberry (Bereris thunbergii) and European barberry (B. vulgaris) are incredibly invasive shrubs. Both species are wildly spread throughout the northern US. Barberry forms dense swaths of vegetation that block out all natives. If you are out in Michaux State Forest in early spring, the first shrubs to green up are the barberry. They are EVERYWHERE. It is not eaten by deer, which then chow down on the natives even more strongly.
If the invasive-ness of barberry isn't enough to get you to remove it, then maybe this will - ticks LOVE it. Barberry creates just the right conditions for a tick breeding operation.
When removing barberry, be sure to get all of the roots. Bag up all of the plant material, including berries, and dispose in the garbage. Alternatives include inkberry holly, native bush honeysuckle, and so many more.
Are there any landscape professionals out there who can explain to us why on Earth plants that are on the PA DCNR invasive plants list are allowed to be grown and sold within the state?