Grow Dinner Plate Dahlias in Colorado

The first year I started my cottage garden in Colorado, I planted Dinner Plate dahlias almost accidentally. I did not know what to expect when I picked up a sack of mixed dahlia tubers from a warehouse store. When I opened the bag and saw a jumble of dried, oddly shaped tubers, I thought, There’s no way these will grow. Still, I dug a few holes, planted them, and hoped for the best.

By late summer, I was stunned. Towering stems held up huge, vibrant dahlia blooms in bold colors, and my garden bursts with life. Friends and neighbors complimented me, and I knew I had found a must-have flower for my Colorado garden. There’s truly a “wow factor” to a garden filled with dahlias.

One day, I brought over a bunch of deep purple dahlias to my neighbor. She admired them and immediately sent me to her friend’s house, a local dahlia enthusiast. When I pulled up, I couldn’t believe my eyes—row after row of dahlia varieties in every color imaginable: purples, reds, oranges, yellows, and even greens.

That was the moment I was hooked. Since then, I’ve been growing dahlias every summer. With over 20,000 dahlia varieties, you can count on an explosion of color and texture in your flower beds. Whether you're new to gardening or a seasoned grower, dahlias are a magical addition to any Colorado landscape.

If you're serious about growing dahlias, investing in a simple growing guide is a low-cost way to boost your success. Most dahlia tubers come with basic planting instructions—don’t overlook them! These foundational tips can distinguish between a thriving garden and a disappointing season.

Here are some essential tips to help your dahlias bloom beautifully:

• Don’t overwater when planting tubers – Too much moisture can cause rot before the plant can sprout.

• Water generously once growth appears – When green shoots break through the soil, increase watering to support strong stems and blooms.

• Choose a full-sun location – Dahlias need 6–8 hours of sunlight daily to produce vibrant, showy flowers.

• Give tubers room to grow – Space plants at least 18 inches apart to allow air circulation and reduce the risk of mildew.

Whether growing dinner plate dahlias or smaller varieties, these simple steps will help you grow strong, healthy plants and maximize your dahlia season.

Truth be told I bought the bulbs because I liked the name, I also thought the magenta and white striped photo on the package of bulbs looked unusual and beautiful. After the first year, I discovered many other varieties that grew exceptionally well in my Colorado Springs garden. Because Colorado has short hot summers these flowers flourish here. A recent visit to a community garden showed me many other varieties including Spider Dahlias with a lemon chiffon colored middle and magenta outer petals.

This Soil Kit Will Last for Years

Dahlias like an acidic type of soil (6.5-7.0) so test your soil and adjust accordingly.

I plant the tubers when the ground is warm and the soil is loose adding in manure and some bone meal and working it in to the soil. Using the bulb planter I dig a 6" deep hole and put the tuber in horizontally covering each one with soil. Because these are large flowers make sure you plant at least 18" apart. Every grower will tell you, that unlike other bulbs, these ones should not be watered until the sprouts have appeared.