Clematis tangutica, or Russian virgin’s bower, is an unusual clematis in that its prolific blooms are bright yellow rather than the more common pink, lavender or white. Hardy in USDA Plant Hardiness Zones 3 through 11, this plant is often grown as a climbing vine, although it sometimes appears in beds and borders or scrambling over a wall.
Like all clematis, clematis tangutica thrive in rich, cool soils. Amend the soil with compost or rotted manure and plant clematis with the crown 3 to 4 inches beneath the soil surface. This plant tolerates full sun to partial shade, but keep its feet cool by growing other plants around it or by mulching with wood chips.
Water the soil to keep it evenly moist — not soggy or dry. Clematis tangutica grows vigorously, reaching 15 to 20 feet high in one season. Train it to a strong trellis or support system. Clematis wraps its petioles (leaves) around structures to climb; structures less than 3/4-inch diameter work well. Attach sturdy fishing line to arbors or trellises to provide a satisfactory surface for your plant to climb. Fertilize clematis in the spring after pruning with an all-purpose, balanced fertilizer.
Pruning clematis is a source of confusion for many gardeners but is based on when the plant blooms. Clematis tangutica blooms in late summer to early fall, so prune it in spring when the plant first emerges. Cut the plant back to the ground, leaving two healthy buds that stand 6 to 8 inches high. Discard the pruned foliage to prevent diseases.
Clematis tangutica is vulnerable to powdery mildew, rust, stem cankers and fungal spots. Insects such as aphids, scale insects or earwigs may also afflict it. Water early in the day and avoid wetting the leaves if you are concerned about diseases, such as powdery mildew. Treat clematis with fungicides and prune out diseased foliage 2 inches below the affected area. Fungal diseases are rarely fatal to clematis, advises the University of Illinois, and plants rebound after pruning. Spray clematis with a stream of water to remove aphids and other insects or use an insecticidal soap for severe infestations.