Annual Wildflower Tests Challenge Conventional Wisdom

Lee Gordon, CNPS San Diego Gardening Committee

Wildflower seeds sown in June 2016 and left uncovered produced a nice bloom of wildflowers in April 2017: Eschscholzia californica (poppies), blue Gilia capatita, yellow Camissoniopsis bistorta (sun cups), and white Cryptantha intermedia (popcorn flower).

Conventional wisdom says that the best time to sow annual wildflower seeds is in the fall, just before the rains, and that seeds should be covered with a thin layer of soil to protect them from predation. This conventional wisdom may be wrong. Tests in Scripps Ranch and Poway (San Diego County) suggest that it is better to sow wildflower seeds months in advance of the fall rain, and that covering seeds may actually prevent them from germinating.

The first test was in my friend Bob’s back yard in Poway. I mixed packets of seeds, and he sowed them in three adjacent areas in July, September and early November. He covered half of each area with a thin layer of soil and left the other half uncovered. The worst results were in the November area covered with soil. The best were from the half of the September sowing that was left uncovered.

I tried a similar test in a small Scripps Ranch open space, dubbed the “Canyonito” by CNPS member Sarah. I sowed seeds in three adjacent areas in June, September and November, leaving them uncovered. Workmen later covered the last two areas with a thick mulch to suppress weeds. No wildflowers grew in these areas at all. However, the area sown in June was left alone, and this area had a beautiful spring bloom. This test shows that you can get good results from sowing seeds early.

In a third less formal test, I sowed wildflowers on a hillside brush management zone in Scripps Ranch in October. This is an area of trimmed chaparral with considerable bare dirt. Two of the species behaved differently here compared with how they grow in the wild. While some plants grew to a normal size, many more grew late and stunted. Plants that grow stunted like these are uncommon in the wild.

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Fall’s Bounty of Seeds and Fruits

by Meghan Walla-Murphy
This article is part two in a four part series about seeds. Previous articles: Spring | Summer

photo by Meghan

photo by Meghan Walla-Murphy

Supposedly, hitchhiking is illegal in California; yet, the fall season is filled with hitchhikers. You, your dog or your cat may each become unwitting accomplices in this illicit activity. A late summer or autumn hike through an open meadow, dense riparian growth or even thick chaparral will reveal these travelers looking for an easy ride. Fur filled with burrs, pant-legs covered in clinging seeds, socks painfully filled with foxtails. Fall is the time of harvest, but it is also the time for seeds– often enclosed within fruits– to search for a new destination to flourish and spread their genetic vigor. Continue reading

Summer Seeds

By Meghan Walla-Murphy

Grindelia stricta

Grindelia stricta. photo by Meghan Walla-Murphy

The long languorous days of summer offer an opportunity like no other time of the year. The many day-lit hours present the possibility of intense growth and busy activity while warm sultry temperatures slow us down and beg us to take a siesta.  We shed layers of clothes and amplify under the warming glow of the California sunshine. During summer humans are capable of both concentrated production and aimless wandering. We work and play. Our gardens bolt and need tending, but paradoxically we stand back and let the plants do their thing.  A juxtaposition of vibrating energy and slow relaxation. Continue reading

The Life Cycle of Seeds: Spring

By Meghan Walla-Murphy
(Part one of a four-part series about the physiology and life cycle of seeds) Part 2

As vernal equinox approaches and spring begins to take hold, hillsides, meadows, grasslands, and even gardens transform. Tender, bright green shoots overtake the brown dormancy of winter. New growth reaches for the sun as the days lengthen and temperatures rise. Winter and spring storms converge over California and drop precious and necessary moisture. And yet while our eye is drawn to the green above ground, our attention should be directed below, toward the seeds responsible for the freshness of spring. Continue reading