High Elevation Gardening Web Log "Blog"

Last summer I conducted a face-off between two plants well suited to our high-altitude, four-season climate, the Rocky Mountain Penstemon, with dark green smooth leaves and two-foot high stalks of purple flowers, and the Lambs' Ear, with fuzzy silver leaves and knee-high shoots of small magenta flowers. I was surprised by the outcome of the duel - within three months the Lambs' Ear completely swamped the penstemon and would have killed it had I not intervened.

Weeds serve several roles in the garden. First, they function as an indicator of soil fertility - botanical translators of a soil's pH (acidic versus alkaline), texture (percentage of sand, silt and clay), and structure (how rapidly water and nutrients move through it). In Weeds and What They Tell by Ehrenfried E. Pfeiffer, the Field Bindweed, a petite member of the Morning Glory family, indicates soil lacking in organic material. In contrast, dandelions grow where the soil has been prepped with fertilizer, compost, and water for lawns, orchards and vegetable gardens, having evolved to take advantage of cultivated land.

Second, weeds are free, and may be used as the green part of the one part green (grass clippings) to two part brown (dry leaves or shredded newspaper) compost equation. Three notable exceptions because of their status as invasive species include Dalmation Toadflax (known as Butter 'n Eggs on the East coast), dry Cheatgrass, and Field Bindweed.

Third, what passes as a weed may be a seedling mimicking a weed. Tumbleweeds (any plant that breaks off after drying and rolls away in the wind) and Ponderosa Pine seedlings look identical until they are an inch high. While tumbleweeds grow leaves of the same length, pine seedlings grow both short and long needles with the characteristic turpentine smell of the conifer family.

In the spring of 1996, I surveyed my new home's weed population as part of my no-lawn program. Along with the red cinders left by the previous owner, there were tiny Sunflower sprouts, Field Bindweed tendrils, and a low-growing Potentilla. In May, I noticed three spiky, blue-green blades slipping from under the Potentilla. Out of curiosity, I put the weedling trio on probation because they did not look like a grass or cultivated bulb. In late June, I was rewarded with blossoms from of one of Arizona's most beautiful natives - the Sego Lily. A perennial wildflower that blooms between May and July, the Sego Lily is also known as the Mariposa Lily, and is the state flower of Utah. In Flagstaff, they speckle the hillside above East Cedar Avenue near the Cedar Safeway, and a few grow in undisturbed areas of Buffalo Park.

Weeds can be annoying, sabotaging our emerald-green lawns, and overwhelming our efforts to establish vegetable gardens and flower beds. They can also be nature's unexpected gift, revealing soil characteristics and attracting valuable pollinators. The pine seedling that was almost misidentified as a tumbleweed is now about five feet high. The three strange sprigs, remnants of a high country meadow along Schultz Pass Road, have bloomed every June since 1996, and probably many summers before that. Since weeds may not always be weeds, they add mystery to our gardens.

Freddi Steele is a Master Gardener volunteer and a former naturalist with the National Park Service. Dana Prom Smith is a Master Gardener volunteer and the coordinating editor for the Master Gardener Column. He can be contacted at stpauls@npgcable.com. For gardening questions, please call the Master Gardener Hotline at 774-1868 ext.19 or visit the Master Gardener Web Site: highelevationgardening.arizona.edu.