Saturday, August 7, 2004

wind

Wind can be such an exasperating thing. In a typical spring, winds here in the Albuquerque frequently gust to 50 mph, and the howling that results causes the cats to hide under the bed. I howled myself, but in frustration as I tried to garden on that first warm weekend. The pots flew around the yard, mulch flew in my eyes, and the wind even knocked me off my feet as I bent down to plant. Just as bad were the snapped lush stems of the lilies, and the shredded dehydrated leaves of my newly purchased plants. I discovered that wind like this could occur at any time of the year here. I could fight the wind, but a garden enclosed with sturdy structures was not what I had in mind. But how would I make lemonade out of lemons?

First I had to give up the idea of control. You can’t control the wind here. So I had to accept that there would be some days that I don’t garden outside, just as during snowy or rainy days. Then, instead of just choosing plants simply on the basis of wind tolerance, I decided to focus on the things that I like about wind. I realized that I loved the look of the wind as it rippled in waves across grass, adding movement and rhythm to the landscape. I planted Calamogrostis x acutifolia ‘Karl Foerster’ which has a neat upright form that I craved.

The tough, thin stems seem to easily take all sorts of abuse from the wind and bounce back up after every gust. Pennisetum setaceum has a similar effect, but use it as an annual in cold climates, and only plant sterile varieties as it can invade wild areas. Other grasses that do “the wave” include Andropogon gerardii, or Big Bluestem. This plains grass forms clumps of upright bluish foliage to six feet tall if irrigated, 3-4 feet if not. The turkey-foot seed heads wave in the wind, reminding me of a gospel choir with their hands in the air. The whole plant turns beautiful shades of red, orange, and russet brown in the fall. I have lined a walkway with Big Bluestem and interplanted with Salvia azurea, whose long stems topped with sky blue flowers sway in unison with the grass. I have been wary about falling for the charms of Mexican feathergrass (Stipa tenuissima). It has silky seed heads which ripple delightfully in the wind, but later the delicate seed heads matt together like a mangy dog and the plants self-seed aggressively. New Mexico feathergrass (Stipa neomexicana) and the closely related needle-and-thread grass (Stipa comata) are other valuable members of the genus Stipa. These two species produce eight-inch pale green awns that shimmer like silk and seem to float in a breeze. Last summer the banks of this grass along I-40 west of the city were breathtaking. The early season awns drop after several weeks, leaving attractive sheaths. These last the rest of the summer and into winter. Be careful of the awns if you have pets. This plant isn’t called needle-and-thread grass for nothing. Little bluestem (Schizachyrium scoparium) sways beautifully in the wind also, and has the added attraction of russet fall and winter color, and seeds that catch the late afternoon light in fairy-dust sparkles. I prefer the staunchly upright forms of the grass, which stay upright even through snow, but for a more relaxed garden, plant seedlings, which have a variety of forms and colors, from summer silver to green, fall reds to tans, upright or slouching.

It’s not just grasses that can produce the wave effect, although with larger leaved plants it takes a larger number of plants to see it. A uniform planting makes the wind more apparent. Choose plants that have flexible leaves, but leaves that tolerate the wind without shredding. If the leaves have undersides that are a different color, so much the better. (One of my favorites for this effect is Convolvolus cneorum, but it isn’t hardy here). The common blue spirea (Caryopteris x clandonensis) provides this two-tone effect, with the added benefit of sky blue flowers. Unfortunately, there are few native plants that fit all criteria. Chamisa ((Chrysothamnus nauseosus) does, if you don’t mind the sweaty sock smell of the fall flowers and can prune it back severely every winter (unpruned plants have less wind effect). Coyote willow (Salix exigua) shows off the wind to great effect if you have a damp ditch to grow it in. It also has the benefit of red winter stems. Some of the daisies show the wind well if they have a uniform flower height. Ratibida (prairie coneflower) swings nicely, as would a bank of Perky sue (Hymenoxys argentea) whose leaves have a silvery underside. Of the penstemons, Penstemon palmeri has enough flower stems and height to show off the wind. There needs to be enough plants to be effective however, and the plants are short-lived but reseed well in gravel-mulched soil. The very stiff stems tolerate high winds well, which is essential during their spring bloom. Expect to lose a stem or two.

A neighbor’s quaking aspen leaves flutter in the lightest breeze, looking like a living Coca-Cola billboard. Unfortunately this high mountain tree has a number of faults in this climate, mostly its great thirst and poor tolerance to heat, but also its invasive roots that can damage foundations. In the right climate and situation, however, it is breathtaking. There are other plants that produce the flutter effect. Boston Ivy (Parthenocissus tricuspidata) also shares the quality of rhythmic movement. At UNM recently, a friend and I were hypnotized by the waves of wind turning the leaves. The effect was emphasized by the contrast between the moving leaves and the large plain flat wall. In higher winds, the thin leaves of tree yuccas such as Y. elata or Y. rostrata shimmer, twisting without bending. Visually, they are an applauding audience. For the shimmer effect, grasses rise to the moment again. Eragrostis trichodes (Sand Love Grass), a Southwestern native, has a similar effect, but on a smaller scale, to 2-3 feet. Be aware that sand love grass is said to seed with abandon and is short-lived. You’d expect Indian Ricegrass to have a similar effect, but it doesn’t, the clouds of seedheads blow in the wind as a block, like a matted hair net. Chasmanthium latifolium (Northern Sea Oats), and the aptly named Quaking Grass (Briza maxima) have larger seedheads which wriggle in the wind, those of Briza maxima giving it the common name also of Rattlesnake Grass. As a child, I loved picking a stem and shaking them to hear the rattlesnake sound.

Which reminds me: don’t forget about the sound effects of the wind. Aside from the goose-pimple inducing howl and the house shaking of high winds, the wind can make wonderful music in the garden. Grasses like Northern Sea Oats produce a soothing rustling, as does bamboo or other tall grasses, poplar trees and many others. Seedheads are natural wind chimes and rattles, such as mature poppy pods. The foot-long bean-like rattling pods of the neighbor’s honey locust tree change this tree from ho-hum to wow. Larger leaves blow in the wind, and when fallen, the leaves can make rustling, clattering little cyclones. Those with a firm texture, like cottonwood, are especially effective.
In designing a garden that takes advantage of the wind, I realized a great benefit. These are experiences you can’t capture with a camera. You have to be there to enjoy it. But when the wind reaches that peaking howl that makes the cats hide under the bed, do as they do in the south. Throw a hurricane party.

Friday, July 9, 2004

Rhus trilobata (Three-leaf Sumac)

Rhus trilobata (three-leafed sumac) is a native shrub that is one of the more commonly planted natives in Albuquerque. This is easy to understand, because it is a compact shrub, grows quickly, and uses very little water. The three-lobed leaves are attractive and medium green to olive green. These reportedly turn color in the fall to red, orange and yellow. In late summer through winter, three-leafed sumac may have red berries at the tips of its branches, and although attractive, these aren’t usually produced in enough numbers to be impressive from a distance. Rhus trilobata’s growth can be accelerated by irrigating, and can thus grow more than 24 inches a year, although with greater growth, the plant can become lanky and weak, needing pruning. As the plant reaches the desired size, the water can be decreased to maintain plant size. Continued irrigation will produce a shrub that can reach 6-10 (or more) feet tall. Without irrigation, Rhus trilobata generally remains half that size. According to David Cristiani, the natural range of Rhus trilobata extends from the Colorado plateau south to Roswell.

There are several problems with this plant as it is used in Albuquerque today. The plants sold are generally not what you see growing in our foothills. Instead, what is sold is a broad leafed form, the color ranging from medium green to grass green. Some plants have broad cupped leaves. In contrast, the plants native to the Albuquerque foothills tend to have small leaves, with widely spaced leaflets, which are dark olive green. Although the broad-leafed plant is attractive in its own right, I suspect that these plants originated from plants of the higher rainfall areas. This may account for the significant differences between the wild form, and the form that is generally sold. Although the nursery plants tolerate drought fairly well (you may see them defoliate in the midsummer along Tramway), I have always been disappointed in the fall color of the sold plants. Although they are promoted as being colorful, I haven’t seen any in Albuquerque with the flaming colors that are seen in books. This may be because the climate isn’t right for these plants to develop color, and they just turn brown and fall off instead. The native plants in the foothills do turn color in the fall, but are more commonly an equally attractive plum purple rather than red-oranges.

Rhus trilobata is generally propagated from seed. Although this is beneficial for maintaining genetic diversity, the seedlings will be variable in quality. Judith Phillips warns that cuttings are tricky however, and timing is essential. This year, I attempted to root cuttings of a vigorous, small leafed plant with purple fall color and fall leaves that lasted into December. I took four-inch tip cuttings in mid-June. The spring growth was complete and the stems had firmed but were not woody. Two half-inch strips of bark were peeled from the lower ends of the cuttings. They were then dipped in a 10:1 dilution of Dip ‘N Grow brand rooting solution, and inserted into a mixture of small perlite and seed starting mix. The pot was placed in a plastic bag, and I left on vacation. 3 weeks later, I noticed growth on the cuttings, with roots showing though the drainage holes. Plants were then potted separately. If you have plants of Rhus trilobata that have especially good form and good consistent fall color, you might try taking cuttings. Or let me know, I would love to have a few!