Three Native Annuals to Direct Sow Now

By Bryan Fischer– Curator of Plant Collections at The Gardens on Spring Creek

Annuals seem to be used less and less in residential gardens in the region. This might be due to their reputation as fertilizer-hungry, water-demanding resource hogs. And, while such a reputation is deserved by some annuals—especially overbred bedding plants whose leaves disappear beneath their garish floral displays by June—it couldn’t be farther from the truth for others. Some annuals, especially native varieties, make great additions to perennial beds. They can help reduce weed pressure in temporary bare spots like sidewalk edges or gardens undergoing renovation. And, in the case of recently planted gardens, they’re a healthy part of a garden’s development, providing easy and attractive filler in the spaces between young perennials and shrubs. Native annuals, in particular, do all this while proving superb forage for wildlife, including birds, pollinators and insects. 

Most seasoned gardeners are familiar with our native bee balm (Monarda fistulosa). For those who aren’t, this perennial can be found sporadically in meadows in our foothills, where the plants color the verdant, grassy patchwork between streams and ponderosa pines with dense clusters of bubblegum pink flowers on three-foot stems. What many folks don’t realize, however, is that there is an annual bee balm native to the southern and central Great Plains—the plant blooms in just a few months from seed and has the added benefit of flowering in clusters up the length of its shorter stems rather than just at their tops. Called Monarda citriodora, lemon bee balm can be purchased as seed online or, occasionally, at your local nursery. Plants are best in full sun and with occasional irrigation. They’ll reach one to two feet tall and can be grown in most zones except for high mountain gardens. Monarda pectinata offers a similar-looking plant that is more likely to be a short-lived perennial (though it can be annual) with near-white flowers. It’s native to our immediate region.  

Also calling the Front Range home, snow-on-the-mountain (Euphorbia marginata) offers a taller option for those with more bed depth or taller plant material to fill between. The species thrives in moderate-to-dry soils and full sun, and especially appreciates some soil disturbance, like in a freshly dug garden. Though its flowers are technically minute, they are surrounded by 3-foot-wide collars of flashy green and white bracts that draw an enormous amount of attention once the species hits its stride in early summer. Pro tip: Just be sure when looking for seeds of this plant that you are buying the native snow-on-the-mountain (a Euphorbia) and not the garden nightmare-inducing Eurasian perennial Aegopodium podagraria, which goes by the same common name.  

The final plant in this piece, like lemon bee balm, is found naturally in the central great plains, through much of Kansas and up to the Colorado border. Omitting it from your garden simply because it’s not found within our state boundaries would be remiss; it’s become a staple in my gardens for its easygoing, attractive presence and impressive appeal to native insects. Commonly called partridge pea, the species is slow to start in spring, waiting for warm soils and a bit of moisture. Once sprouted, it moves fast—four or six weeks—to produce a bushy, full-grown plant sporting ferny foliage. Many years, my plants are flowering by early July and continue showing off through frost. Though short in height—just over a foot high—the plants make great smotherers for annual weeds without stressing or outcompeting established perennials. 

All three of these easygoing and easy growing annuals can be started from seed bought in bulk and broadcast over your garden. I typically do this in mid-late winter, though it works fine in spring, too. Just be sure to provide a good seedbed with plenty of nooks and crannies to settle into for germination. Gravel mulch does this well, while leaf and wood mulch do not. Bare soil will also work if you’re willing to water daily during germination. Once your plants have a few sets of true leaves, reducing watering frequency will help them establish and adapt as they prepare for summer’s heat. Watering once to twice weekly is plenty for these hardy annuals as they mature; no fertilization is necessary. Happy planting!