...but every situation we face helps us learn more possibilities, especially when we share with each other what we've observed. So we're always glad to hear whether you used our suggestions, and what happened next.
Last year I wrote to ask you if I could cover my Oregon grape with leaves all winter to prevent frostbite. It's an infant plant, only about 18 inches high, so it wasn't hard to do. And I'm pleased to report that it worked perfectly. If I hadn't gotten a bit ahead of myself and uncovered it just before the last extreme cold snap of spring, it wouldn't have lost even one leaf. As it is, the damage is limited. Finally the poor thing has an opportunity to grow more in a year than it loses! - N.P. -
We're glad to have helped.
Oregon grapeholly (Mahonia aquifolium) is hardy to zone 5. In some winters in that cold, it may defoliate but will develop replacement foliage. Because N.P. is growing the dwarf grapeholly (M. a 'Compactum') which is only a few feet tall, it's possible to cover a significant portion of its wood and leaves with an airy mulch such as fallen leaves, or site it where snow will do that job. There, the plant may do well even in zone 4.