Plants for Clay Soil: Perrenials

In this post I am adding perennials to my list of plants that can thrive in clay soil, and partial sun. This is part of my quest to create a native/Mediterranean, drought-tolerant, deer-tolerant entrance to our home, with seasonal interest, low maintenance, and consideration for its Asian heritage. Perennials are herbaceous plants that live two or more years. Some die back to the ground after blooming for a period of dormancy, and then re-emerge the next season; others are evergreen throughout the year. I have included a few plants that are already growing in our planters. Most are not California natives, but they are solid performers that thrive where they are planted, on little water. Why rip them out?

• Agapanthus africanus (Lily of the Nile) – 2-3 feet tall, with 2-3 feet spread. Deep purple or white rounded flower umbels grow on 4 feet stalks, with glossy, strap-like leaves (monocots, with parallel veins). They are extremely drought tolerant, and flourish in sun or part sun. They are native to South Africa, which is home to some very tough, beautiful plants. We have quite a few Agapanthuses growing in our planters. I love their shiny leaves, and floating flower globes through the summer months. Amaryllidaceous family.



Agapanthus africanus (Lily of the Nile)

• Heuchera spp. (Coral Bells or Alum Root) – 1-2 feet, with 1-2 feet spread. White or pink flowers; leaves are basal, dark green, and somewhat hairy. Variations include H. micrantha (Crevice Heuchera), and “Martha Roderick” with pink flowers. Compatible with oak. Saxifragaceae family.
• Iris douglasiana (Douglas Iris) – 1-2 feet, with 1-2 feet spread. Colors range from pale blue, lavender, and mauve to deeper shades of blue and purple. Also in yellow, copper, cream and white. Dark green leaves, usually evergreen. Starts blooming in January or February near the coast, and continues through May. Compatible with oak. We have a patch of deep blue iris that comes back faithfully every spring. I’d like to add white. Iridaceae family. 
• Juniperus spp. (J. procumbens or J. horizontalis) – 12 inches, with 3-4 feet spread. Blue-green to green carpet. Small, white flowers in spring, and glaucous blue fruit in the fall. Drought tolerant once established, and deer tolerant. We have several of these attractive, low-growing evergreen plants in the planter area. I may decide to relocate them, or encourage growth in a new direction. Cupressaceae family.

• Lithodora diffusa  – 6 inches high, with a 2 feet spread, mat forming. Masses of deep purple, five-lobed flowers, with deep green lanceolate leaves. Summer flowering, but ours seems to bloom throughout the year. Requires well-drained soil, but is doing fine in our planter. Deer resistant. Boraginaceae family.
• Mimulus spp. (Bush Monkey Flower or Sticky Monkey Flower) – 1-3 feet, with 1-3 feet spread. Tubular flowers in shades of orange, apricot, yellow, and red. They are short-lived perennials, so need to be replaced every few years. Attracts hummingbirds. Scrophulariaceae family.
• Monardella villosa (Coyote Mint) – 1-2 feet, with 1-2 feet spread. Lavender to rose flowers that bloom July through August. Aromatic gray-green leaves. Attracts butterflies. Needs sun or part sun. Drought tolerant to moderate water in heat. Requires well-drained soil. Deer tolerant. Good for dry slopes, rock gardens, and containers. Compatible with oak. Lamiaceae family.
• Penstemon heterophyllus (Foothill Penstemon) – 1-2 feet, with 2 feet spread. Tubular flowers on spikes in many colors. Evergreen foliage along stems. Attracts humming birds. Variations include P. heterophyllus “Margarita BOP" (Bottom of the Porch) in purple, and “Blue Springs” in deep blue. Scrophulariaceae family.
• Unidentified (snapdragon?) – 1 foot, with 1 foot spread. White blossoms with traces of yellow, resembling violets. Woody stem and lanceolate, notched leaves. This is a tough, tenacious perennial that blooms through neglect and drought, despite the clay soil. I don’t know its name, but we purchased one from Annie’s Annuals in Richmond, CA five or six years ago. Possibly from the Scophulariaceae family.



Unidentified snapdragon (and tough performer)

• Unidentified (Scotch heather?) – 1 foot, with 2-3 feet spread. Tiny bell-shaped flowers on branch tips in shades of pale pink, lavender, and purple. Scale-like dark green leaves. Blooms mid-to-late summer. Requires moderate water, but thrives on little water where planted. A native of Scotland, Ireland, Russia, so may appeal to my family roots. Ericaceae family.

Good sources:

• Annie's Annuals and Perennials:  http://www.anniesannuals.com/
• California Flora Nursery (no mail order, but an hour north of Oakland/Berkeley): http://www.calfloranursery.com/