Is Heather Good for Retaining Walls?

Heathers growing in their native European setting

Plants that require good drainage grow well in retaining walls. The porous wall materials alleviate the build-up of excess moisture around plant roots. Heathers thrive in this type of situation. They are matte-forming evergreen plants with shallow root systems. They will provide your walls with texture and color throughout the seasons.

A Look at Heaths and Heathers

Heathers produce an abundance of bell-shaped flowers.

Heaths and heathers are often lumped into the same group. They are actually two different plants with similar characteristics. At a glance they look similar, but they have very different foliage. Heathers (Calluna) have scale-like foliage, bloom in the fall, and are hardy to USDA zone 5. Heaths (Erica) have needle-like foliage, bloom in winter and are hardy to USDA zone 6. For overall toughness, the callunas usually win out. Though there are taller plants within these groups, the low-growing varieties are best for retaining walls.

Heather Plants for Retaining Walls

Mixing plants will create a patchwork of color.

Heathers are valued for their ever-changing foliage colors, as well as for their flowers. There are newly developed varieties that have longer bloom periods. Aphrodite produces red flowers from late summer until the first hard frost. Annette blooms pink, and Melanie produces white flowers. Spring Torch has mauve flowers but is planted for its cream variegated foliage that turns attractive shades of red and orange in fall. Firefly has similar mauve flowers, but the foliage turns a vivid brick red when the nights turn cool.

Heaths for Retaining Walls

Heaths bloom later in the season than the heathers. They are at there best in the middle of winter when color is most appreciated. Erica carnea 'King George' is a very good choice for retaining walls. The maximum height is 6 inches, so little shearing is required. The flowers are pink, and the foliage is deep green. Erica darleyensis 'White Perfection,' is a free flowering white variety. For tight spaces, there is an extra compact variety called Pirbright rose. It has pink blooms and is 6 inches tall.

Pruning and Care

The sparse tendencies of heathers can be alleviated with yearly shearing.

It is important to keep retaining wall plants in shape. Encourage horizontal growth by carrying out twice-yearly pruning. Heaths and heathers bloom at different times, so prune each plant directly after it has completed flowering for the season. Shear off spent flowers and any irregular growth. Calluna's can take pruning well, but Erica's should only be lightly sheared. They are more sensitive to cold winds and very hot sites.

References

• Fine Gardening: Calluna vulgaris 'Spring Torch'
• Gardening made Easy: Growing Heaths and Heathers
• Great Plant Picks: Calluna vulgaris 'Firefly'
• Oregon State University; Landscape Plant Database: Erica carnea
• Great Plant Picks: Erica darleyensis 'White Perfection'

Resources

• The Heather Specialists: Watering