Dan Songster, former President of the Orange County Chapter of the California Native Plant Society (OCCNPS), provided this Plant of the Month article featuring Seaside Daisy for September.

• What: Erigeron glaucus–Seaside Daisy
• Type: Evergreen herbaceous perennial 
• Light: Likes full sun but appreciates partial shade inland
• Soil: Adaptable
• Water: Moderate

Basics

As its common name implies, Seaside Daisy (Erigeron glaucus) is a perennial plant in the daisy family that grows on the coastline of California and also north into coastal Oregon. This sturdy, low growing plant has a long flowering season, blooming profusely through spring and most of summer in shades of lavender and pink, with large yellow centers. These vigorous, no-nonsense perennials provide a cool spot of color in a coastal garden. The flowers are attractive to butterflies and bees.

This cheery evergreen daisy is easy to grow, stays low (from 12 inches to 18 inches tall), with branching, nodding stems. Depending on which species or cultivar you pick, it can range anywhere from 18 inches to three feet wide. 

Garden Uses

The Seaside Daisy is perfect used in front edges of various planters, beds, borders, or massed on a shallow slope. The colorful shrub will embellish any little spot, crack, or crevice. Some folks grow them as a blooming component in meadow plantings along with Yarrow and a couple species of native grasses. I also grow them in containers where they do quite well. Content in well-draining sites, even those with sandy soil, they often bloom for months on end and can easily withstand periodic dry spells.

These plants are so versatile! As Bert Wilson of Las Pilitas Nursery wrote, “A bit of nature for a sunny perennial garden in San Francisco or part-shade garden in Los Angeles. Mix with monkeyflower, various wood mint, Douglas Iris, Seacliff buckwheat, Seaside golden yarrow, or Hummingbird Sage.” 

A wonderful plant for pollinator gardens, Seaside Daisy is a good nectar source for butterflies and many different pollinators. After the seeds form, you will see juncos and finches flock to the plant to dine! 

Note: If you are the cautious type, it should be noted that various sites show this plant as being toxic to dog, cats, and horses. After investigation, I find that most good sources say it may be “mildly toxic if eaten in quantities,” with symptoms ranging from nausea to diarrhea. If that is the case, perhaps it should be planted away from small children?

Care  

This lovely daisy thrives with a little summer water and tolerates wind and (just in case you live on the beach) salt spray.  I provide a little extra water during the late spring and early summer and find that helps extend its bloom. As Las Pilitas Nursery mentions, “Out of its range, seaside daisy likes a little extra water and hates dust. So, go out there and wet your whistle while washing off the daisies every couple of weeks and you’ll both be happy.” 

Bert’s experience also notes: “In richer soils it looks better, and blooms more profusely than it will in sandy or rocky soils. In inland gardens, plants in full sun will often flower spectacularly throughout spring but often burn to a crisp during summer…individual seaside daisy plants have a useful garden life span of two to seven years.”

In our Orange County climate, we can grow them in full sun quite easily but a respite from blazing heat of the inland part of the county helps them look fresher longer. 

Pruning

Randy Baldwin and friends from San Marcos Nursery advises, “When plants get lanky, cut back to 1 to 2 inches of stem in late fall.” I have seldom had to do that, but when done as the cooler months arrive, new sprouts of growth occur and the plants are happy. However, that kind of hard pruning involves timing. Pruning in summer months can cause plant dieback as the plant struggles with heat and dryness while attempting to add new foliage.

Another form of pruning (recommended by all) is deadheading spent flowers. This can be done anytime–it encourages a second round of blooms and makes the plant a bit tidier.

Pests? I have never had a problem with any of our routine garden insects, though I have found it can harbor slugs and snails if kept too moist.

Notes

Several cultivars are available to choose from. Here are some I have grown: 

Erigeron ‘Arthur Menzies’ was the first Erigeron glauca selection I remember coming across. It is a very tight/compact mound of the straight species with a bit more lavender in the flower color. Not as showy as our more recent cultivars and not found much in nurseries anymore (sigh!).  

Erigeron glaucus ‘Bountiful’ (Bountiful Seaside Daisy) – An evergreen perennial that forms clumps to 6-10 inches tall by 2 feet wide with gray-green foliage and 3-inch-wide lavender daisies with chartreuse to yellow centers from spring to fall. The selection ‘Bountiful’ was made by Bart O’Brien at Rancho Santa Ana Botanic Garden (now California Botanic Garden) in Claremont, California. ‘Bountiful’ is a noted improvement over other Erigeron glaucus cultivars with compact growth and very large lavender flowers.

Erigeron glaucus ‘Cape Sebastian’ (Cape Sebastian Seaside Daisy) – This low growing form of seaside daisy grows to only 3 to 4 inches tall and spreads to 18 to 24 inches wide. This is the smallest and tightest growing of the Erigeron glaucus selections.  The one-inch-wide daisy composite flowers, with lavender rays and yellow central disk flowers, cover the plant profusely in the spring through summer with sporadic flowering throughout the rest of the year. 

Erigeron glaucus ‘Cape Sebastian’ was a selection made from plants growing near Cape Sebastian State Park, south of Gold Beach Oregon, where it was selected by Brett Hall, the University of California Santa Cruz Arboretum Manager.

Erigeron ‘WR’ and Erigeron ‘Wayne Roderick’ (Wayne Roderick Daisy) Wayne Roderick introduced two of the most common cultivars that were named for him: Erigeron ‘Wayne Roderick’ and Erigeron ‘W.R.’. Wayne provided many nursery propagators with these two Seaside Daisies. Both are good plants but very different.  Over the years the names have been switched around and many plants have been labeled incorrectly and sold as its cousin. Randy Baldwin muses, “The initials “W.R.” stand for Wayne Roderick, the legendary bay area plantsman, who passed away in 2003….We are sure that if Wayne was still with us, he would find this all of this confusion quite amusing.”

My thoughts are that the one named Erigeron ‘Wayne Roderick’ is actually a cultivar of the straight species of E. glaucus. Yes, it is an evergreen perennial with large 1-inch-wide composite daisy flowers. But they have dark purple flowers and greenish yellow ray flowers in the center that, unlike other of these Seaside daisy cultivars, rise on 18 inch stalks above the foliage clumps in the winter to spring. 

The other plant named Erigeron ‘W.R.’ was a plant Wayne reportedly found as a spontaneous garden seedling. Based on its habit and looks, he determined that it had crossed with another species of Erigeron. This plant was introduced using this name given to it by Nevin Smith, of Winter Green Nursery and Suncrest Growers fame and author of the book Native Treasures. It is considered more heat tolerant of the two and its lavender daisies sit on slender stalks about 10 inches above low rosettes of narrow leaves.

Share Your Experience

Have you grown Erigeron Glaucus or any of its cultivars? Let us know how this perennial performs in your garden.