Coprosma repens (Mirror Plant)

Coprosma repens, commonly known as mirror plant or looking-glass plant, is a strikingly vibrant evergreen shrub that captivates with its glossy foliage and robust growth.

Coprosma repens – Mirror Plant: An In-depth Look

Coprosma repens is renowned for its shiny, leathery leaves that reflect light, giving the plant its common name. The leaves often have a variegated pattern with colors ranging from deep green to hues of gold, red, and orange, especially in colder temperatures.

Native: This plant is native to New Zealand, where it is found in coastal areas and forest margins. It belongs to the coffee, madder, or bedstraw family (Rubiaceae), which includes popular genera such as Coffea (coffee), Gardenia, Cinchona (quinine), Ixora, and Rubia (madder).

Plant Type and Habit: Coprosma repens is an evergreen shrub that maintains its foliage year-round. It has a dense, rounded habit, often used in gardens for its architectural form and the lustrous quality of its leaves.

Size: Typically, it grows about 3-6 feet tall (90-180 cm) and can spread equally wide, forming a dense, bushy appearance. In exposed environments like cliffs, it takes on a prostrate form, while in sheltered regions, it can grow as a small tree up to 26 feet (8 meters).

Flowers: The flowers are small, inconspicuous, and usually white or greenish-white. Flowering occurs in late spring to early summer, depending on the climate and conditions. After flowering, female plants produce small, egg-shaped, orange or red fleshy berries in late summer to fall. They are attractive and contrast beautifully against the glossy foliage.

Foliage: The foliage is the standout feature with its high-gloss finish that looks almost polished. The leaves are oval-shaped and can change color with the seasons, becoming more intensely colored in colder weather.

Hardiness: It is relatively hardy, suitable for USDA zones 9 to 11. It can tolerate mild frost but needs protection from harsh winter conditions.

Uses: Widely used in landscaping for hedging, screens, or as a container plant due to its vibrant color and dense growth. It is also popular in coastal gardens due to its salt tolerance.

Wildlife: The berries attract birds, particularly in winter when food is scarce, making it a valuable plant for supporting local wildlife.

Toxicity: Coprosma repens plant is considered non-toxic, although it’s still advisable to discourage pets and children from ingesting any plant material as a precaution.

Deer and Rabbits: Generally, Coprosma repens is deer resistant.

Drought / Salt Tolerance: It exhibits good drought resistance once established. It is also highly tolerant of salt spray and coastal winds, making it an ideal choice for seaside gardens and exposed, windy locations.

Invasiveness: Coprosma repens is currently reported as invasive in South Africa. It’s important to monitor and manage its growth to prevent it from overtaking native plant species.

Benefits: Aside from its ornamental value, the plant provides excellent shelter for small wildlife due to its dense structure. Its salt and wind tolerance make it an excellent choice for coastal conditions.

Coprosma repens (Mirror Plant) and Acanthus mollis (Bear’s Breeches)

How to Grow and Care for Coprosma repens

Coprosma repens is highly tolerant of salt spray and coastal winds, making it an ideal choice for seaside gardens and exposed, windy locations.

Light: Coprosma repens thrives in full sun to partial shade. More sunlight encourages brighter leaf colors.

Soil: Plant in moist, well-drained soil with a neutral or slightly acidic pH.

Exposure: Choose a site that is somewhat protected from extreme cold winds but can handle coastal breezes.

Planting: Plant in spring or autumn to give the plant time to establish before extreme weather conditions. Dig a hole twice as wide as the root ball and just as deep. Mix in some compost or aged manure to enrich the soil if needed. Place the plant in the hole so that the top of the root ball is level with the soil surface, then fill in and firm the soil around the base.

Water: Water regularly to keep the soil moist but not soggy until the plant is established. The roots are likely to rot if the soil remains muddy. Once established, Coprosma repens is somewhat drought tolerant but benefits from occasional watering during prolonged dry spells, especially in hotter climates.

Fertilizer: Feed with a balanced, slow-release fertilizer in early spring to support new growth. Follow the manufacturer’s instructions for the correct dosage and method of application.

Pruning: Prune in late winter or early spring before new growth starts. Regular pruning helps maintain the desired shape and size, encourages bushier growth, and can rejuvenate older plants.

Mulching: Apply a layer of organic mulch around the base to conserve moisture, suppress weeds, and maintain a cool root environment. Use bark, shredded leaves, or other organic materials.

Winter Protection: In cooler regions (outside USDA zones 9 to 11), provide some winter protection such as mulching around the base or using frost cloths over the plants during particularly cold snaps.

Coprosma repens Propagation – A Step-By-Step Guide

Propagating Coprosma repens is a relatively straightforward process that can be done through cuttings, allowing gardeners to create new plants that are true to the parent’s characteristics.

Timing: The best time to take cuttings is in late spring through summer when the plant is actively growing.

Selecting Cuttings: Choose healthy, non-flowering shoots from the current season’s growth. These should be firm and slightly woody at the base.

Preparing Cuttings: Cut a 4-6 inch section of stem just below a leaf node using a sharp, clean knife or secateurs. Strip the lower leaves off the cutting, leaving two to four leaves at the top. If the remaining leaves are large, consider cutting them in half horizontally to reduce moisture loss. Though not always necessary, applying a rooting hormone to the cut end can enhance rooting success. Dip the base of the cutting into the rooting hormone powder or solution.

Planting: Fill a pot with a mix of perlite and peat moss or a well-draining potting mix formulated for cuttings. Insert the cutting into the potting mix, ensuring that at least two nodes (where the leaves were removed) are below the surface. Firm the mix around the cutting to secure it in place.

Environment: Place the pot in a warm, bright location out of direct sunlight. A greenhouse or plastic cover can be used to maintain humidity around the cutting, which helps prevent it from drying out before it roots. Ensure the potting mix remains moist but not soggy.

Rooting: Root development typically occurs within 4 to 8 weeks, depending on the conditions. To test if roots have formed, gently tug on the cutting; resistance indicates root growth. Once the cuttings have rooted and show new growth, begin to acclimatize them to less humid conditions by gradually removing any plastic covering. When the plants are sturdy enough, transplant them into individual pots with standard potting soil.

Transplanting: Before planting them outdoors, acclimate the new plants to outdoor conditions by gradually increasing their exposure to the elements over a week or two. This process is known as hardening off. After hardening off and once they’ve grown sufficiently in their pots, the new Coprosma plants can be transplanted to their final position in the garden during a mild time of year, either spring or autumn.

Coprosma repens: Pests, Diseases, Common Problems

Coprosma repens is generally robust and resistant to many pests and diseases, but like any garden plant, it can occasionally encounter problems.

Pests

Mealybugs: These are a type of sap-sucker that secretes a white, waxy substance which can lead to the growth of sooty mold. Treat infestations with insecticidal soap, neem oil, or by removing them manually using a cotton swab dipped in alcohol.

Scale insects: These small, sap-sucking pests attach themselves to the stems and leaves, potentially causing yellowing or stunted growth. Scale can be controlled by wiping them off manually with a cloth dipped in soapy water or using an appropriate insecticide or neem oil.

Diseases

Root rot: This is usually a result of overwatering or poor drainage. Ensure that the soil is well-draining and that you’re not watering the plant too much, especially during cooler months.

Leaf spot: Spots on the leaves can be a sign of fungal infection, often exacerbated by wet conditions. Improve air circulation around the plants, avoid overhead watering, and remove affected foliage. Fungicidal sprays may be necessary for severe cases.

Common Problems

Leaf Drop: Coprosma repens may drop leaves in response to sudden changes in temperature, particularly in colder climates or when moved indoors for winter. Gradually acclimate the plant to new conditions to minimize stress.

Discoloration of Leaves: Leaves might turn yellow due to poor nutrition, particularly a lack of nitrogen or iron. This can be corrected with appropriate fertilizers. Variegated varieties may revert to green in too much shade; if this is undesirable, increase light levels.

Frost Damage: While Coprosma repens is somewhat frost-tolerant, sudden severe frosts can damage foliage. Protect plants with frost cloth or move container plants to a sheltered location during cold snaps.