If you’ve ever stood in your garden, coffee in hand, wondering how on earth your neighbor coaxed a dinner-plate-sized dahlia into existence, you’re not alone. In Routt County, dahlias carry a certain mythical reputation, like unicorns, but with better color options. The good news? With a little strategy and a sense of humor, these dramatic divas can absolutely thrive in our mountain gardens.

First things first: dahlias are not hardy in the Yampa Valley. They’re summer guests who expect sunshine, attentive care and a guaranteed ride home before frost. They grow from tubers, not bulbs, and those tubers need warm soil (around 60°F) before they’ll even think about waking up. In Routt County, “warm soil” is more of a philosophical concept than a date, but late May to early June is your realistic window.

Choose firm, healthy tubers that look like an enthusiastic pile of oddly shaped potatoes. You only need one visible “eye,” or growing point, to get started. Plant them 4–6 inches deep in well-drained soil. Resist the urge to water right away. Yes, I know, it feels wrong. Let the tuber wake up slowly. Once green shoots appear, begin watering consistently, keeping soil moist but never soggy. Give them water, yes, but they’re not auditioning to be water lilies.

Sun is non-negotiable. Aim for 6–8 hours of full, unapologetic Colorado sunshine. Lodgepole-filtered light does not count. These plants are also heavy feeders, but skip fresh manure. Too much nitrogen leads to the botanical equivalent of a teenage growth spurt: lots of lanky foliage, not nearly enough flowers. A balanced, low-nitrogen fertilizer keeps blooms coming without the drama.

Speaking of drama, let’s talk wind. Dahlias grow tall, bloom big, and collapse with all the flair of a soap-opera star in distress. And in Routt County’s breeze (which is just Wyoming casually blowing us a kiss) staking early is an act of mercy. Loop stakes, tomato cages, bamboo stakes, livestock panels, use whatever you’ve got. Just don’t wait until they’ve already down for the count.

For bushier plants and more blooms, pinch the growing tips when plants reach about 12–16 inches tall. It feels cruel for five minutes, but I promise it will feel brilliant the rest of the summer. Deadhead spent blooms regularly, and before long your garden will resemble a floral fireworks display.

Eventually, frost will arrive, usually the night after you’ve bragged about how great everything looks. Let the foliage blacken, then dig up the tubers. Rinse gently, allow them to cure for about a week, and store them in a cool, dark place with good air circulation. Ideal storage is 40–50°F with slight humidity. Think somewhere between “root cellar” and “basement.”

Growing dahlias in Steamboat is equal parts science, optimism and stubborn hope. But with a little planning and a willingness to embrace a bit of chaos, mountain gardeners can grow truly spectacular blooms, even in thin air.

Sarah Storm is a CSU Extension Master Gardener in Steamboat Springs whose casual interest in dahlias has turned into what some might call hoarding, she prefers “strategic floral abundance.”

Have gardening questions? The CSU Routt County Extension Office and Master Gardener Help Desk are available Thursdays, 10 a.m.–1 p.m., May through September. Call (970) 879-0825 or email rcextension@co.routt.co.us.