Dahlberg Daisy

What’s blooming in the area: Apache plume, roses, trumpet creeper, silver lace vine, canna, datura, silver-leaf nightshade, bindweed, Heavenly Blue morning glories, purple phlox, bigleaf globemallow, bouncing Bess, white sweet clover, goat’s head, yellow and white evening primrose, velvetweed, toothed spurge, purslane, stickleaf, pigweed, mullein, heliopsis, broom snakeweed, chamisa, Tahokia daisy, French marigolds, sunflowers, golden hairy aster, goldenrod, horseweed, goat’s beard, wild lettuce, chicory; two goats were eating where man tried sheep last year.

What’s blooming in my garden, looking north: Golden spur columbine, coral beardtongue, hartwegii, chocolate flower, blanket flower, coreopsis, Mexican hat, black-eyed Susan, yellow cosmos, chrysanthemums; first squash to produce fruit is an Eight Ball zucchini..

Looking east: Floribunda rose, hosta, garlic chives, large-leaf soapwort, Crimson Rambler morning glories, sweet alyssum, winecup, hollyhock, sidalcea, scarlet flax, California and Shirley poppies, pink bachelor buttons, African marigolds.

Looking south: Rose of Sharon, perennial sweet pea, sedum, Sensation cosmos, zinnia.

Looking west: Caryopteris, buddleia, Russian sage, catmint, leadplant, flax, David phlox, purple ice plant, Silver King artemisia, Monch aster, purple coneflower.

Bedding plants: Sweet alyssum, snapdragons, petunia, tomatoes, Dahlberg daisy

Inside: Aptenia, zonal geranium.

Animal sightings: Quail, hummingbirds, gecko, grasshoppers, ants, bees.

Weather: Last useful rain, August 6. After days passed without even a storm passing through and cooler mornings, some plant began to react: squash and tomatoes wilted, some cherry leaves turned yellow, ladybells went out of bloom.

Weekly update: Wildflowers don’t recognize political boundaries. They define their territory by soil characteristics too minute to interest cartographers.

Dahlberg Daisies like the shallow lime soils that overlay clay in the Tamaulipan brushlands that stride the lower Rio Grande on the gulf coastal plain that reaches to the Sierra Madre Oriental in Mexico and the Balcones Escarpment in Texas. R.E. Rosiere found the perennials growing with buffalo grass under scrub in Live Oaks County midway between Corpus Christi and San Antonio.

Move them beyond zone 9 and they become annuals. Gardeners in Plano and Gillett, Texas, told Dave Whitinger, their plants perpetuate themselves with volunteers. In Dallas, Sally Wasowski found no one who could winter them over, but a number who could naturalize them.

Move them to an area that gets more annual precipitation than San Antonio’s 25 inches, and they have problems with humidity. In Tampa, a Dave’s Garden contributor plants them in October and November after the humidity drops so they can bloom before it rises again.

Move them to an area that’s hotter and drier, and they die out in summer. C. A. Martin reports they will, however, reseed themselves for years in Phoenix.

Move them into containers or hanging baskets and they become a commercial product. Although they were offered in the mid-1950's by Thompson and Morgan as Golden Fleece, they were rarely mentioned by garden books until seedsmen began looking for plants that could withstand temperature and moisture extremes on decks and balconies.

Move them to my yard, and they survive the summers but don’t reproduce. I first planted them with marigolds, hoping to introduce some variety into my north facing yellow garden. The marigolds rarely survived the transition from nursery conditions and those that did usually disappeared with the grasshoppers.

Dahlberg Daisies have no such problems, although most years they remain fairly small plants with single composite flowers rising from bright green, ferny leaves. With last year’s moisture, the plants expanded in late summer and bloomed until late October. This August has been drier and my plants switched from flower to seed production this past week.

Book publishers care a great deal more about legal boundaries than do plants. Jean Louis Berlandier discovered Dahlberg daisies near San Antonio in 1829, but they rarely appear in field guides because the part of their range that lies in this country, the triangle of south Texas between the Gulf of Mexico and the Rio Grande, doesn’t have many book buyers, and the Spanish-speakers to the south are excluded by copyright laws and international distribution agreements. It doesn’t help editorial assistants that botanists changed its name from Dyssodia tenuiloba to Thymophylla tenuiloba.

Fortunately for me, nurseries have found a large enough outdoor living market in southern California and Arizona, that plants are usually available in Santa Fe or at a local hardware. I’ve bought plants with labels from Hardy Boys in Colorado and McK in Arizona. Most of the time, they arrive with generic Pixie labels that somehow suit a wildflower slipping from the rangelands of south Texas and northern Mexico into suburban life.

Notes:
Martin, C. A. “Thymophylla tenuiloba,” available on-line.

Rosiere, R.E. “Rio Grande Plains (Tamaulipan Brushlands),” range website.

Wasowski, Sally. Native Texas Plants, 1988, with Andy Wasowski.

Whitinger, Dave. “Dahlberg Daisy,” Dave’s Garden website with viewer contributors from ambercoakley, dale_a_gardener, and YardKat.

Photograph: Dahlberg daisies growing with blue-grey leaved California poppies and volunteer grasses, 25 August 2007.