With exotic flowers resembling orchids, the desert willow (Chilopsis linearis) looks too fragile for its harsh desert origins.
Its ruffled blossoms smell of violets, bloom from spring through hard frost and attract hummingbirds. Their colors range from pale pink to reddish-purple and, rarely, white. Long, narrow willow-like leaves emerge late in spring, making this small tree less susceptible to damage from the untimely freezes so typical on the Front Range. Desert willow is a good fit for small gardens, with its multiple trunks growing more upright and arching than they are wide, reaching about 10 feet high and 6 feet wide.
Of course, I had to have it.
For the past 20 years I’ve planted a desert willow almost every spring. Not one has survived, despite mature specimens all over the Denver area. Finally, I decided these trees weren’t meant for me. I resigned myself to just enjoy them in other people’s gardens.
But last fall after I told a friend I was never going to try another desert willow, he offered me a white variant he’d purchased earlier in the year but couldn’t find a place for in his garden. Dismissing my reservations, he assured me that anyone could grow this plant. With trepidation I accepted his gift, certain that this, too, would not end well.
Pride now at stake, I gave a lot of thought to the desert willow’s cultural requirements. This tree is native to the high deserts of the Southwest, where temperatures occasionally dip to minus 15. At my house, minus 30 is not uncommon, so I figured winter cold was killing them.
But desert willows survive temperatures this low in other gardens by dying down to the ground and then growing back. What I needed was a microclimate that is hot in summer but protects the tree’s roots from extreme cold in winter. Remembering a desert willow thriving planted up against a wall at a friend’s home in Littleton, I started looking around for wall space.
The problem was that every wall on my property was already providing a for some other desirable plant. It was while taking out an overgrown smokebush and lilac from a niche on the east side of my house that I realized this former shade garden was now the hottest spot in my entire garden in summer.
But in winter, the east-facing orientation prevents snow from melting, helping mitigate the temperature swings that confuse non-native flora into breaking dormancy too early.
Also a plus: I had never amended the soil here. Plants with desert origins don’t appreciate vegetable-garden loam; they actually prefer the low-nutrient, high-mineral soils that once defined the Eastern Plains before we all decided to grow bluegrass and shade trees.
With all that this microclimate had going for it (from a desert willow’s perspective), I still was shocked to see tiny green leaves appear a couple of weeks ago. It might be sheer coincidence. This past winter was exceptionally mild.
But who knows? Maybe 2012 will be the year that my desert willow curse came to an end.
Marcia Tatroe’s most recent book is “Cutting Edge Gardening in the Intermountain West” (Johnson Books). E-mail her at mtatroe@q.com
