Adapted from Growing Food in the Southwest Mountains: A guide to high-altitude, semi-arid home permaculture gardens, 4th edition:
It has been a banner year for barberries in Flagstaff. The shrubs are laden with the tasty fruit all over town. They are prolific fruit bearers. I tell people that barberries are one of the most reliable fruit species for the high elevation Southwest.Barberries are an excellent fruit for urban foragers; just make sure you collect the berries from clean areas not treated with pesticides and not next to roads with a high traffic volume (and thus vehicle pollution).
Barberry shrubs have evergreen, holly-like, prickly leaves that turn red during cold weather; each berry contains one large seed. There are two native barberry species in my region, creeping barberry, Mahonia repens and Fremont barberry, M. fremontii. Oregon grape, M. aquifolium, is native to the Sierra Nevada and Pacific Northwest. Japanese barberry also grows well here. Berberis is another barberry genus. Barberry species are found throughout much of the temperate and subtropical regions of North and South America, Europe, Asia, and Africa. M. aquifolium is an invasive plant in Europe.
In Flagstaff, barberries are literally everywhere because they are a popular low maintenance ornamental landscape plant. They grow in front of my house where they receive harvested monsoon rainwater from the roof through the repurposed section of fire hose attached to a gutter. They also grow along the side of my house and receive greywater from an outlet from our washing machine. The steady water supply makes the shrubs extra-productive in terms of fruit yield. I also collect the berries from neighbors’ yards (technically common area in my townhome complex). Every year I have conversations with neighbors who see me picking the berries and had who had no idea that barberries are edible and tasty.
I wear a latex glove to protect my right hand from the prickly leaves and berry juice staining. The berries hang in clusters. The fastest way to collect them is to gently grab a cluster and pull the berries off the stems without squashing the berries. Many berry clusters are hidden beneath and behind the leaves so you need to bend down and move branches aside as you pick.
I take the mass of moist seeds left over from processing and fling them with a spoon into areas where I want more barberries to grow, impromptu permaculture seed balls. I have significantly expanded the shrubs on the side of my house this way.
The small berries with purple juice have a complex Concord grape-like flavor, excellent for juice and preserves, jelly and jam. The berries are very tart due to a low sugar content and need added sweetener. Middle Eastern and Central Asian barberries are made into a dried spice, while English cooks have used their species to make jams and jellies (see this article in The Guardian for cooking ideas using dried barberry spice). Like most berries, barberries are high in vitamin C and other vitamins, minerals and healthful phytonutrients. The roots and stems contain berberine, a powerful plant chemical that should only be consumed for medicinal purposes under a health care provider’s supervision; the bright yellow color of the inner bark comes from the berberine.
See my second post in this series, Processing barberries for fresh eating, freezing or canning. Also see my third post, Making & canning barberry jam.