Creeping barberry (Berberis repens) is a hardy shrub. It originated in Northern California, as well as the Sierra Nevada. This species grows best in well-drained loamy soils.
I. Appearance and Characteristics
Berberis repens commonly known as creeping mahonia, creeping grape holly, or creeping barberry, is a species of Berberis native to most of the western United States and two western provinces of Canada.
Berberis repens is an extremely short shrub, usually just 2–20 centimeters tall, very occasionally reaching 60 centimeters. The bark on stems becomes gray-purple or gray in color and are not hairy. The plants spread by modified underground stems (rhizomes) that are about 1.5–5.0 centimeters under the surface of the mineral soil. Despite the short above ground height its roots can reach as much as three meters into the ground.
The leaves are compounds with an odd number of leaflets attached to the main vein. Usually leaves have five or seven leaflets, but may have just three. The length of a complete leaf structure will be 10–30 centimeters. The upper surfaces of the leaflets are smooth and dark green while the undersides are lighter green and covered in fine, downy hairs. The edges of the leaflets have between six and twenty-four teeth tipped with spines. Although it is evergreen, in the fall and winter leaves will partially or completely turn bronze or red in color when exposed to sun.
The flowers grow in a densely packed inflorescence without branches called a raceme. Each one will have between ten and fifty flowers and be 4–10 centimeters long. The yellow flowers bloom early in the spring and are quite fragrant. Local conditions determine the exact timing of the bloom which may be as early as February or as late as June. The flowers have six yellow sepals outside the six yellow petals with the tip of each split. Each flower has a single pistil, but six pollen producing stamens which emerge when the petals or sepals are touched.
Berberis repens has quite striking dark purple-black berries with a matte blue blush that contain a single seed and resemble a grape. Each berry is roughly round, about 6–10 millimeters in size, and juicy in texture. The flavor of the berries is quite tart with an astringent quality, and generally more attractive to birds than humans.
Creeping grapeholly generally increases in response to disturbances in forest ecosystems such as mild fires, severe fires, and logging, though it may be eliminated in the short term by severe intensity fires. As a long lived plant with a protected root system and seeds that are presumed to persist in the soil it recovers quickly from low intensity fires. The above ground stems and parts of the plant in the forest humus are vulnerable to fire damage, but resprouts from undamaged rhizomes in the mineral soil. It decreases over time when the forest canopy is too dense, though it can tolerate significant shade and increases as other plants are negatively impacted by acidification of the soil by conifer trees.
The leaves and stems are slightly poisonous to livestock and not very palatable. It is considered poor forage for both horses and cattle, but is considered fair forage for sheep in Utah and Wyoming. It is browsed by various wild animals. Elk and white tailed deer both consume creeping grapeholly in the winter and to a greater extent when the weather is mild and there is less snow covering the plants. Mule deer also readily consume the leaves and stems during the winter and early spring. Under certain conditions it may make up the largest portion of their diet in winter. It is also eaten to some degree by the Mountain cottontail rabbit and heavily eaten by the snowshoe hare in winter.
The berries are consumed by many species of bird and small mammal, but they are not a significant portion of their diet. Other than the sharp-tailed grouse, no specific bird associations have been recorded.
II. How to Grow and Care
Creeping barberry generally requires minimal upkeep, making it a suitable choice for gardeners of all levels. It thrives in well-draining soil and full to partial sunlight. Special care points include ensuring the soil remains consistently moist without becoming waterlogged and protecting the plant from extreme winter chill. Pruning is not frequently necessary but can be done to maintain shape and encourage denser growth.
Sunlight
Creeping barberry requires ample amounts of sunlight to maintain its brightly colored leaves with a minimum of 6-7 hours of direct sunlight. As it is remarkably tolerant of a variety of conditions, it will grow in partial sun and even under only 80% of full sun. However, when grown in shade, its colorful foliage will turn greenish.
Temperature
Creeping barberry handles temperature extremes well, being able to survive temperatures down to -25 ℃. As it is a low feeder, it also doesn’t require much watering. Drainage is an important factor, and in a normally draining soil, you can water your creeping barberry only when the top 5 cm of soil go dry.
Watering
Originating from arid regions, creeping barberry has adapted to conserve water, making it relatively drought-tolerant. It thrives with a watering schedule of once every 1-2 weeks, maintaining a balance without over-saturating its roots. As an outdoor plant often found in rocky terrains, creeping barberry benefits from well-draining soil that mimics its natural habitat, promoting healthy growth cycles while preventing waterlogging.
Soil
Creeping barberry prefers well-drained, slightly acidic soil (6.0-6.5 pH). It can grow in all soil types (sandy, loamy and clay), but you should add certain amendments. If you are planting in quick-draining soil, mix in some peat moss or compost to improve drainage. Organic compost can also improve the acidity of your soil.
Fertilizing
Fertilizing creeping barberry promotes robust growth and vibrant flowering. Spring and early summer are ideal for a balanced fertilizer (10-10-10), applied monthly at a rate of 1/2 pound per 100 square feet. Transition to a high-nitrogen formula if growth appears weak. Fertilizer spikes or granular types, worked into the soil around creeping barberry, reduce the chance of root burn. Less is more; over-fertilization can harm creeping barberry’s natural growth, so follow package directions. Pause fertilization in late summer to prepare creeping barberry for dormancy.
Pruning
Creeping barberry does not necessarily require pruning, but pruning can significantly increase its vigor. Also, if planting creeping barberry as a hedge plant, you should get an early start in properly shaping it. By trimming branches, you can thin the crown to improve ventilation and sunlight. This reduces humidity and the development of leaf pathogens (they thrive more in humid and dark places).
Pruning should be performed in spring to avoid exposing bare and growing tissues to too much moisture during autumn or frost damage during winter. Trim the old and infected branches, and branches that grow outside of the shape you desire. The golden rule is that not to cut away more than 1/3 of its canopy, and all cuts should be on a slight angle facing away from the bud. Always wear gloves when trimming creeping barberry. Remember to disinfect your tools at the beginning to minimize the chances of cross-contamination.
Propagation
Creeping barberry propagates best through cuttings during spring and summer. It has a moderate propagation difficulty. Successful propagation is indicated by new growth and root development. For better results, use rooting hormones and maintain consistent humidity.
Transplanting
The prime time to transplant creeping barberry is during Autumn (S3), as this allows for roots to fully establish before the growth period in Spring. Preferred location for creeping barberry is in full sun to part shade. Ensure it’s in a well-draining area and remember, creeping barberry dislikes overly wet soils. Always handle with care during the transplant to avoid root damage.
Repotting
When repotting creeping barberry, a low-growing ground cover, do so every 2-3 years to accommodate its spreading habit. Spring is ideal, allowing creeping barberry to recover during its active growth phase. Choose a shallow, wide pot for its sprawling roots, ensuring ample room for expansion. Post-repotting, maintain moist soil without overwatering to encourage healthy regrowth. An engaging task, repotting nurtures creeping barberry’s vibrant, enduring nature.
III. Uses and Benefits
- Ornamental uses
Creeping barberry is a popular ground cover in cooler climate gardens and is also used as a low-growing specimen shrub. Its attractive foliage provides almost year-round appeal, while clusters of small spring flowers attract bees and other pollinators to the garden. Dark berries in the fall continue to add garden color and bring birds to the area as well.
- Other uses
The berries are edible, but are considered bitter. Wild foraged berries are used to make jellies or wine with the addition of sugar.
The Tolowa and Karok Indians of Northwest California used the roots for a blood and cough tonic. The Hopi, Paiute, Navajo, Shoshoni, Blackfoot, Cheyenne, Mendocino, and other tribes also used the plant for medicinal, food, and ceremonial needs. Native Americans also used the wood of the stem to produce yellow dyes to stain woven baskets.
