Sunday, August 10, 2014

Natural Selection

Weather: Cloudy afternoons, last rain 8/1; the rivers are still running brown.

What’s blooming in the area: Hybrid roses, silver lace vine, trumpet creeper, rose of Sharon, datura, bouncing Bess, purple garden phlox, alfalfa, sweet pea, Russian sage, yellow yarrow, zinnia, cultivated sunflowers.

Beyond the walls and fences: Tamarix, velvetweed, buffalo gourd, yellow evening primrose, purple mat flower, pink and white bindweed, Queen Anne’s lace, goat’s head, leatherleaf globemallow, horseweed, wild lettuce, Hopi tea, plains paper flowers, tahoka daisy, golden hairy asters, black grama grass.

In my yard, looking east: Large-flowered soapwort, Jupiter’s beard, hollyhocks, winecup mallow, sidalcea, pink evening primrose.

Looking south: Betty Prior, Fairy and miniature roses.

Looking west: Caryopteris, Johnson’s Blue geranium, catmint, calamintha, David phlox, ladybells, sea lavender, Mönch daisy, purple coneflower.

Looking north: Yellow potentilla, golden spur columbine, Mexican hat, black-eyed Susan, chocolate flower, blanket flower, coreopsis, anthemis.

In the open, along the drive: Fernbush, buddleia, larkspur, white yarrow, yellow cosmos.

Bedding plants: Snapdragon, sweet alyssum, blue salvia, moss rose, French marigold, gazania.

Seeds: Reseeded Sensation cosmos from last year’s plants, bachelor buttons.

Animal sightings: Rabbit, geckos, small birds, bees, grasshoppers, large and small black ants.

Weekly update: This has not been a great year for seeds. There was no rain in the spring or early summer. It was difficult to keep seeds wet with surface watering.

Then, there were the grasshoppers and, in my yard, the rabbit. One day I would see some seedlings, the next they were gone.

The Cosmos Bipinnatus that are blooming now are seeds from last year’s plants that reseeded themselves. Ones for the Dazzler variety emerged the end of May.

The rabbit left them alone. Perhaps the stems were too developed by the time the animal was grazing my yard. Or, maybe they were mature enough to have some defensive trait that discouraged nibbling.

Natural selection works in wondrous ways. The original seeds for these plants were sown in 2012 and were blooming by late August.

Last year a few seedlings emerged which began producing flowers the first of August. By late September, the four foot stems were covered with dark red flowers. I left the seeds for the winter.

This year the seeds that came up were next to the walk where they get water trapped by the blocks.

Back on September 17 of 2006 I wrote about the years of breeding it took to shorten the gestation period for flowers from a native of the valley of México so they would appear in northern gardens before frost. Sensation cosmos was introduced in 1930.

In 2003, the Royal Horticultural Society tested seeds. They reported their "trial of Cosmos bipinnatus was very disappointing and showed poor maintenance by the various seed companies and therefore previous awards could not be confirmed."

"Poor maintenance" didn’t mean letting weeds and rabbits take over. It meant seed companies weren’t producing the same quality seed that had earlier.

When Mary Keen complained that year, seed companies implied it was her fault. Chiltern Seeds said they only had had two negative letters in ten years. Its spokesman "stressed that all seed is variable and advised anyone pricking out seedlings to select different heights for the best results."

She didn’t accept that. She’d had good yields before. She knew how to grow Dazzler cosmos.

When she talked to friends, she discovered no one she knew in England could grow cosmos. One thought problems with day length at reappeared.

Companies have been growing seeds in Africa and Latin America to exploit the longer growing season and cheaper production costs. Within a few seasons, the plants may have reverted to the tropical ways that had so carefully been bred out. Seeds from those warm environs didn’t behave like the ones grown in colder climes.

It’s hard to know when the changes were made. Pan American, the owner of Burpee, began using central American sites after World War II. Thompson and Morgan gets most of its seeds from Africa. A representative finally told Keen "there was a problem with selected forms of C. bipinnatus."

Selected doesn’t mean a random few. It means varieties like Dazzler that develop from selecting the best of each generation to encourage the best form. Such strains aren’t the same as hybrids which attempt more fundamental changes to the germ plasm.

Seed origin information on seed packets is deceptive. For a while in the late 1990s, most seed companies included country of origin. They stopped around 2004. I assume the inclusion of the information was a function of rules of the European Common Market, and the omission occurred when rules were changed.

The only seed company which may have been providing honest information was Stokes. They reported their zinnia and Calendula seeds came from Zimbabwe in 1999. Others probably defined origin to mean where they acquired seeds, not where they grew. Holland, Germany and France may have been either the location of growers or wholesale markets.

The seed I planted in 2012 was described as coming from Holland. The Dazzler seed submitted to the RHS trials came from a Dutch company, K. Sahin, Zaden B. V. that had been established in 1982 by Kees and Elisabeth Sahin. Takii Seeds of Tokyo bought them out in 2008.

In 2003, Keen was told the way to guarantee she had good cosmos the next year was to save seeds from those that bloomed in July or take cuttings from good plants and try to winter them over. I let nature do the work by not cutting away seed heads.

In bad times, genes tell. Those paying attention realize Darwin was correct when he reported the workings of natural selection.

My seeds probably came from Africa in 2012 where many may have reverted to tropical habits. The ones that appeared in 2013, by definition, were those that had successfully set seed the year before. The ones now growing again were those that set seeds that dropped or rolled to the protected area by the block.

Notes: To find the posting from 2006, click on "Cosmos Sensation" in the index at the right.

Keen, Mary. "A Disappointing Year for the Cosmos," The Telegraph, 8 November 2003.

Royal Horticultural Society. "Trial of Cosmos from seed 2003: An Invited RHS Trial."

1. Dazzler cosmos flower, 10 August 2010.

2. Santa Cruz river upstream from dam that diverts water to the local ditches, 8 August 2014.

3. Dazzler cosmos flower, with fewer disk florets, 10 August 2014.

4. Cosmos plants growing near block walk, 29 June 2014.

5. Debris from high waters caught on the local Santa Cruz dam, 8 August 2014.

6. Closer few of the dam, 8 August 2014.

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