Plant This, Not That
Native Plant Alternatives to Common Garden Plants
By Jennifer Bousselet
Over the past fifteen years I have seen trends come and go in the Colorado green industry and it seems we are now poised at the precipice of a new gardening trend: native plant gardening. Some gardeners have requested Colorado native plants at garden centers for years, but they have been the minority. Until now. In fact, in the three years I have worked for the nonprofit Colorado Native Plant Society (CoNPS), I have witnessed an explosion of interest in native plant gardening.
If you have noticed the same thing, you might be wondering ‘why?’ Well, it boils down to two things: pollinators and water. In Colorado we have over 3,000 native plant species. Almost every one of those species have associations with native bees, butterflies, and other pollinators in Colorado too. Sadly, many of our native pollinator populations are in decline. So, as gardeners, any help we can give them makes a difference.
Every year new data comes out about water use in Colorado landscapes and it is always over half of the municipal fresh water use. Our Colorado native plants do require some irrigation to get established but after a growing season or two, little irrigation is needed for them to thrive. That is because they have evolved in our semi-arid climate for millennia.
As a horticulturist, I often am asked where to start with a native plant garden. My answer is always the same: start small. Ideally, in a part of your landscape where the soil is not already amended, as our Colorado native plants thrive in our native soils. While I am no designer, I typically recommend that shrubs be selected first as the ‘scaffolding’ of a garden.
Many gardeners hesitate to purchase plants they are not familiar with, so I will focus on native plant alternatives to common landscape plants. One example is Russian sage (Perovskia atriplicifolia), a wildly popular nonnative shrub that can be found all over Colorado in gardens. It is drought tolerant and attracts bees, although you will notice that most of the bees on the blossoms are European honey bees and not any of our nearly 1,000 native species of Colorado solitary bees.
Rather than planting Russian sage, consider our lovely native leadplant (Amorpha canescens) which has a similar appearance and fills the same niche in the garden. Leadplant also blooms in summer with spectacular purple spiky inflorescences. The growth habit is upright and it has compound leaves like other relatives in the legume family. So, not only is it easy on the eyes but it is a pollinator magnet and is a source of nitrogen in the garden due to its symbiotic relationship with nitrogen fixing bacteria in the soil.
Another familiar shrub is Bumald spirea (Spiraea x bumalda). This nonnative is popular due to unique foliage color and long bloom time. A wonderful native alternative is Apache plume (Fallugia paradoxa), which also has unique foliage color - silvery green with white bark. Apache plume has such a long bloom time – spring until first frost – that the specific epithet ‘paradoxa’ refers to the fact that this plant is a paradox because it blooms and sets seed at the same time, a remarkable rarity in horticulture. Most plants have a season of bloom and then a season of seed ripening. The persistent seed head is an incredible Lorax-like silvery pink plume. It is so beautiful that it graces the front cover of CoNPS’ upcoming book, the 3rd edition of Common Southwestern Native Plants by Jack Carter, Martha Carter, Donna Stevens, and me.
Native shrubs are just the tip of the native plant gardening iceberg. Thankfully there are many resources to help Colorado gardeners gain confidence in choosing beautiful and utilitarian plants. If you visit CoNPS.org you can find free PDF downloads of native plant garden guides for five regions of the state, crafted by a coalition of partners. CoNPS is currently hosting a Virtual Plant Sale with 100 species x size combinations; orders are due by April 15 with distribution on May 5. In June, three chapters of CoNPS – Northern, Boulder, and Metro-Denver – will host garden tours featuring native plants in landscapes. Examples of and resources for native plant gardening are no longer elusive.
Jennifer Bousselot is Special Asst. Professor at Colorado State University in the Dept of Horticulture & Landscape Architecture. She has taught homeowner and college-level horticultural courses, and managed Master Gardener programs in two states over the past 15 years.