Plant Description

Name: Cotinus coggygria "Purpureus"
Common Names: Purple Smoke Bush, Purple Smoketree, Royal Purple Smoke Bush

Cotinus coggygria "Purpureus," commonly known as the Purple Smoke Bush, is a deciduous shrub or small tree celebrated for its stunning foliage and unique, smoke-like appearance of its flower clusters. Native to southern Europe and central China, this cultivar is especially popular in gardens for its striking purple leaves that turn brilliant shades of orange, red, and yellow in the autumn. The bush gets its name from the fine, hair-like filaments that surround the faded flower clusters, creating a hazy, smoky effect, especially visible in summer.

This plant typically grows to a height of 3-5 meters (10-15 feet) and spreads to about the same width, forming a rounded shape. The foliage of the "Purpureus" variety is a deep burgundy to purplish-black color, adding a dramatic contrast to garden landscapes. During late spring to early summer, the plant produces large, airy panicles of tiny yellow flowers. As these flowers fade, the panicles develop long, feathery hairs that give the plant its distinctive, smoky appearance.

Cultivation of Cotinus coggygria "Purpureus"

Conditions:

1. Light: Cotinus coggygria "Purpureus" thrives in full sun to partial shade. For the best leaf color and flowering, it should receive at least 6 hours of direct sunlight daily. In areas with very hot summers, it may benefit from some afternoon shade to prevent leaf scorch.
2. Temperature: This shrub is hardy in USDA zones 5-8. It can tolerate a wide range of temperatures, from cold winters to hot, dry summers. It is quite frost-resistant but may need protection from late spring frosts that can damage new growth.
3. Soil: The Purple Smoke Bush prefers well-drained soil and can grow in a variety of soil types, including sandy, loamy, and clay soils. It thrives in slightly alkaline to neutral soil pH but can tolerate a range of pH levels. Good drainage is essential to prevent root rot.
4. Water: Cotinus coggygria "Purpureus" is drought-tolerant once established but benefits from regular watering, especially during prolonged dry spells. Young plants should be watered deeply to help develop a strong root system. Overwatering or poorly drained sites should be avoided to prevent root diseases.

Planting and Care:

1. Planting: Plant in the spring or fall in a location that receives ample sunlight. Dig a hole twice the width of the root ball but no deeper. Place the shrub in the hole, backfill with soil, and water well to settle the roots. Mulching around the base can help retain moisture and suppress weeds.
2. Fertilization: Fertilization is not often necessary for Cotinus coggygria "Purpureus," but a balanced, slow-release fertilizer can be applied in early spring to promote healthy growth. Avoid excessive fertilization, which can result in lush, green foliage at the expense of flower production and color.
3. Pruning: Prune in late winter or early spring before new growth starts to shape the plant and remove any dead, damaged, or crossing branches. Regular pruning can encourage bushier growth and enhance the foliage display. For a more compact form, cut back the shrub hard every few years.

Propagation

1. Seeds: Cotinus coggygria can be propagated from seeds, but this method is less commonly used because it may not preserve the cultivar characteristics like leaf color. If using seeds, they should be stratified (kept in cold, moist conditions) for a few months before planting.
2. Cuttings: The preferred method for propagating Cotinus coggygria "Purpureus" is from semi-hardwood cuttings taken in summer. Cut a healthy stem with several nodes, remove the lower leaves, and dip the cut end in rooting hormone. Plant in a well-draining potting mix and keep in a warm, humid environment until roots develop.