Being a local native plant, Mahonias can take both our winter wet and summer dry, and can be very drought tolerant once established. Their thick leathery leaves and spiny edges also make them unpalatable to deer.
Most species of Oregon Grape are evergreen, but still turn a rainbow of colors in the fall and winter, giving them more interest than your average evergreen shrub. Spikes of cheerful, fragrant yellow flowers emerge early in spring and turn to blue-black fruit that are edible but more appealing to birds than humans. Most varieties spread via underground runners and make a nice colony, so best to give them room to shine and do their thing!
The ones we use the most here in the Rogue Valley are:
Mahonia aquifolium (Oregon Grape) - This is the taller species of our native Oregon Grape, getting to 6' or more and spreading by underground runners. They look best as a mass planting in a native woodland situation and perform best in shade, but will take some sun. Can be pruned hard if getting too leggy and will quickly fill in. Mahonia aquifolium is resistant to oak root fungus - it's a great plant to grow under native oaks, as it also doesn't need much water.
Mahonia aquifolium 'Compacta' (Compact Oregon Grape) - Pictured above left. This variety will stay about 2' tall and makes a nice, broad colony. New foliage is glossy and becomes matte with age. This plant always looks good, staying full to the ground and cheering up the dark days of winter with its bronzy red winter color.
Mahonia repens (Creeping Mahonia) - This native has a spreading habit and will get about 2-3' tall. It tolerates more sun the the taller Oregon Grape, as well as growing well in part shade, and is very drought tolerant. Its leaves are usually more matte than the upright Mahonia but get the same yellow flowers and blue fruit. Great choice for mass groundcover or under oaks.
Mahonia nervosa (Longleaf Mahonia) - This Mahonia is a little more particular than the other native species; requiring more shade. But it's every bit as drought tolerant as M. aquifolium and M. repens. The leaves are more stiffly upright and bit longer. Makes a nice low shrub or groundcover - around 2' tall - for a shady, woodland garden.