Colorful Mid-Height Shrubs And Trees For Banks

In many California housing developments, roads are created on hillsides and pads bulldozed off for houses. Then the problem becomes how to cover steep banks with plants to hold the soil. In some case banks are steep and extensive. Ground covers often are not sufficient to hold the soil through heavy rains. What is needed is a mix of groundcovers cloaking the ground and deeper-rooted shrubs and trees to grip deeply into the subsoil. Here is a list of possible choices that was created by us for a housing scheme where the landscape was 30 years old and needed replanting with better replacements for plants and more drought-resistant plant choices than those planted by the developer.

Mid-Height Shrubs:  (5 to 10 feet tall)

• Bottle Brush ( Callistemon  ‘Canes Hybrid’): 10 feet tall, 15 feet wide. A big screen, measure so eventual height hits at the right level to see over. Narrow leaves and arching branches with pink-tinged foliage, soft pink bottle-brush flowers in late spring, early summer. Easily pruned to a tree shape. Can be kept smaller by pruning but why have that problem? Instead plant where it can grow to full size.
• Bottle Brush (Callistemon viminalis ‘Captain Cook’): Dense, rounded plant to 6 feet tall and wide.  For border, hedge, or screen. (‘Red Cascade’ is similar with large abundant rosy red blooms.)
• Geraldton Waxflower (Chamaelaucium unicatum ‘Vista’): Pink flowers for long season from fall to summer on rounded drought-resistant shrub, to 6 feet tall, for full sun. Cut back after bloom.
• New Zealand Tea Tree ((Leptospermum scoparium ‘Silver and Rose’): Dense growth habit to 4-to 5-feet tall and wide. Rose-pink, green-centered flowers with bright gray-green foliage. Excellent plant to use as screen high on bank.
• New Zealand Tea Tree (Leptospermum scoparium ‘Gaiety Girl’): Slow growing to 5 feet tall and 4 feet wide. Double flowers are pink with a dash of lilac.
• New Zealand Tea Tree (Leptospermum scoparium ‘Pink Damask’): Dense growth habit to 6 to 8 feet tall and 4 to 5  feet wide. Double ruby-red flowers red tinged leaves. Particularly good screen plant.
• Plumbago (Plumbago auriculata ‘Royal Cape’): Makes a mounding shrub 6 feet tall, 8 to 10 feet wide with large rounded deep blue flowers blooming over a long season. Excellent bank cover when placed away from paths. Give it room to spread. Named varieties are not invasive like the older unnamed type. Good mixed with lantana.
• Pride of Madeira (Echium candicans): (5 to 6 feet tall and 8 to 10 feet wide.) Blue spiky blooms on a gray woody shrub. Dot these around on banks. They will spread from seeds.