2016 June 15
Driving across the California dessert recently in 109-degree dry heat, the landscape was very sere. Only a few dessert plants displayed any color other than beige or brown and they were mostly a silver sage color. It got me thinking about which of my garden plants are the most xeric. Xeric generally means requiring only a small amount of water according to the Merriam-Webster website.
Alamosa doesn't have the high heat of the dessert, but we are very arid. And, of course, we can be very cold in the winter. I do water all of my garden beds, but some are hotter, sandier, and receive less water than others.
My thoughts first turned to plants that are grey-green and have fernier looking leaves. These plants tend to need less water. They have tiny hairs that reflect solar radiation, cooling the surface of the leaf by several degrees. The fernier leaf structure allows the wind to blow through freely thus reducing wind damage. Also, their stomata (the openings that allow for evaporation) close easily and quickly, allowing the plants to retain moisture.
Two shrubs native to Colorado with these characteristics that do well in our yard are Woody Fern Bush (Chamaebatiaria millefolium) and yellow-flowered Cinquefoil/Potentilla (Potentilla). Our Fern Bushs are over five-feet tall, green up in late March, and have showy white flower in late July. Cinquefoil is abundant in the valley and surrounding hills. The wetter the year, the more it flowers.
Buffalo Berry (Shepherdia argentea) and Rabbit Bush/Chamisa (Chrysothamnus nauseosus) also have greyish foliage. Buffalo Berry looks a bit like Russian Olive and is often suggested as an alternative since the olive is on the Colorado noxious weed B list (the goal is to stop the spread of this tree and you're not allowed to buy one in Colorado). Rabbit Bush is native to Colorado's high desserts and has lovely yellow blossoms. An interesting side story is that folks tried to cultivate Rabbit Brush around Buena Vista in order to produce latex/rubber during World War II. However, each shrub requires a fair amount of space and can't be grown in dense patches so it wasn't economically feasible. Both Cinquefoil and Rabbit Bush reseed gently.
Golden/Rocky Mountain Currant (Ribes aureum) has greener foliage and pops up in many places around town – especially where it can find some moisture. I use the berries for relish.
All of these native shrubs do OK in drier spots in our yard, but do better with more moisture.
Artemisia (Artemisia) is a large group of silvery leaved plants that do well in my yard. Silver Brocade Artemisia (Artemisia stellerana) has larger leaves than most of the genus and is related to Dusty Miller which doesn't over-winter here. This year, friends gave me some starts of Mugwort (Artemisia douglasiana). In their yard it grows 5-6 feet tall and makes a good privacy screen. Its stems grow from a substantial colony of rhizomes according to Wikipedia.
Two other Artemisia I have grow 8 – 16 inches high and have fine, small leaves. One I harvested from a yard in the Gunnison area and the other was given to me with the caution that it might take over -- I have it in a spot by itself. None of these need much care and do well in sandy soil. Let me know if you’d like some!
We have two types of tarragon: Russian (Artemisia dracunculoides Pursch) that is not as tasty an herb as French Tarragon (Artemisia dracunculoides). The Russian grows to four feet tall and sends out shoots. It grows with very little additional water but isn't as tasty as the two-foot tall French that doesn’t spread.
Another yellow bloomer is low Golden Rod (Solidago). This year it started blooming in early June and, if deadheaded, will bloom through August. It spreads profusely, so be careful where you plant it. I have it in some spots where I haven't been able to grow much else. By the way, Golden Rod has a bad reputation for causing hay fever in the eastern US; however, that is NOT the case!
One of my favorite xeric plants that has greener leaves is May Night Sage (Salvia memorosa). It's dark purple racemes go well with yellow flowering plants. It can form dense masses and the blooms are long lasting and often rebloom in the fall if deadheaded.
I also love ground covers. Succulent Hens and Chicks (Jovibarba globifera) do well at bed borders that don't get as much water as the bed interiors. I do give them extra water from time to time so they can store up for the drier times.
Two great sedum groundcovers are Dragon's Blood (Sedum spurnium 'Bronze Carpet') and Oakleaf (Sedum ybridum). Dragon's Blood has a wonderful marron color and Oakleaf a nice green leaf with yellow flowers.
In general, I find if I let xeric plants form patches they do better. It allows them to drift to where they work best. Some die off and others sprout. I don't think this works well for those who want a very tidy garden!
“Anybody who wants to rule the world should try to rule a garden first.” Unknown