Low-Growing Parkway Plants Your City Will Love

As a native plant garden writer and consultant I receive many interesting questions about gardening with California native plants. In this continuing series (The Paintbrush, CNPS: San Gabriel Mountains Chapter: http://www.cnps-sgm.org/newsletters.html, “Native Plant Gardening Corner”) I share a few of these questions and answers with you. You may email your own questions to me at Barbara.eisenstein@gmail.com, and check my blog (http://www.wildsuburbia.blogspot.com) to follow my adventures in gardening with California native plants.

Achillea millefolium, Aster chilensis ‘Point St. George’ and Eschscholzia californica. From Wild Suburbia

Q. My city requires that all parkway plants be less than 12 inches in height. Are there any low-growing, native plants that would do well in this space?

In the last issue of The Paintbrush I started a practice of suggesting some native plants that make outstanding garden dwellers. I would like to follow up with another list, this time of plants that are low growing. The above question was actually posed by me. In early April I received a citation from the city for my wild, native plant, parkway garden. Apparently city code requires that plants in the parkway be either grass (lawn) or other ground cover plants no higher than 12 inches. There are, in fact, quite a few nice low-growing, herbaceous perennials.

Here is a list of five sun-loving, low-growers.
1. San Bruno Mountain golden aster (Heterotheca sessiliflora ssp. bolanderi ‘San Bruno Mountain’) is a low-mounding perennial with cheerful yellow flowers from spring to fall. You can remove spent flowers or leave them for the birds. Once established, the plant can be cut back hard in late fall.
2. David’s Choice sandhill sagebrush (Artemisia pycnocephala ‘David’s Choice’) is another outstanding garden performer, with a low, hemispheric form and silvery gray leaves. Clip its flowers and pinch back long stems to foster dense, tight growth.
3. The next one I suggest with a word of caution. Point St. George aster (Aster chilensis ‘Point St. George’) is an aggressive spreader that can be hard to control, once it gets a foot hold. I use it in my parkway beneath the city’s magnolia trees. This is an area where nothing else would grow. Point St. George forms a dense spreading ground cover with lavender/pink aster-like flowers from late spring through summer. It does not look its best in winter.
4. All of the above plants come from coastal areas, though they are accepting of more inland conditions. Fragrant evening primrose (Oenothera caespitosa) is a low growing, spreading desert plant that was a welcome introduction to my parkway. The plant responds to occasional summer water with a burst of soft-pink to white showy, fragrant flowers. It did well for two years in my loamy soil, but prefers heat and well-drained soil. I liked it so much that I have bought another to set out again.
5. Although yarrow (Achillea millefolium) can produce a flowering stalk nearly 3 feet in height, this soft, herbaceous perennial can be mowed or cut back to meet city code. Island Pink and Rosea both spread and produce showy pink flower clusters. Mow this adaptable ground cover after it blooms, or leave the flowers for the birds – if your city will allow it.

Oenothera caespitosa From Wild Suburbia

Parkways often house shallow-rooted, city-chosen street trees. These spaces are especially difficult to deal with. Use mulch directly beneath the trees, but further down the strip consider planting the following ground covers that are adapted to part-shade .

1. Woodland strawberry (Fragaria vesca ssp. californica) spreads with creeping stolons that root at the nodes. It enjoys organic soil and shade, and some summer water. You will be rewarded with small white flowers and delicious tiny strawberries. Unfortunately, you may want to leave these for the birds if your parkway is used by neighborhood dogs the way mine is.
2. Coral bells (Heuchera species and cultivars) are among the most popular California native garden plants. This clumping evergreen perennial with small to medium-sized, scalloped leaves gets its name from the dainty bell-like flowers, mostly pink in color, though some selections are red or white. Wendy coral bells is a Rancho Santa Ana Botanic Garden introduction with many stalks of showy pink flowers.
3. Blue-eyed grass (Sisyrinchium bellum and cultivars) is actually a member of the Iris Family that is common throughout much of California in moist, woodland and grassy areas. It prefers good-drainage, but will accept heavier soils if it is not kept overly moist in the summer. Its delightful blue flowers among the grass-like leaves make this a charming garden specimen. Cultivars have been selected with low, dense forms and large blue, purple or white flowers.
4. Idaho fescue (Festuca idahoensis) is an excellent, small mounding bunch grass with very narrow leaf blades. Muse Meadow, Stony Creek and Warren Peak are selections that do well in gardens.
5. Santa Catalina live forever (Dudleya hassei) is a clumping succulent with grayish leaves. It accepts full sun to part shade, but prefers good drainage. Summer water in gardens with heavy soil can rot out these plants. They form a nice ground cover at Rancho in both the mesa area (heavy, clay soil) and the well-drained alluvial soils.

So you can see that even with strict city planting ordinances, you can go ahead with a native parkway garden. There is a longer list of parkway prospects on my wildsuburbia blog. If you have any you would like to add, please contact me.