Calhoun County, AL – Dahlias are my favorite summer flowers—especially the dazzling dinner plate varieties that can produce blooms up to 10 inches across! These enormous blossoms quickly fill a vase with their vibrant charm. Dinner plate dahlias can grow up to five feet tall and require dedicated staking and tying. I recommend starting early in the season, using jute string to secure 12-inch plants. This reduces wind damage and supports the plant as it grows taller. I typically tie each plant 4–5 times over a 10-week period, keeping them safe and upright.
When temperatures rise above 85°F, dahlias can suffer from heat stress. I combat this by planting tubers close together in spring—the overlapping leaves act like umbrellas, shielding plants from excessive heat. Applying a thick summer mulch, such as miniature pine bark chips, helps maintain consistent moisture between waterings.
In hot weather, a 5-foot-tall dinner plate dahlia may need up to 2 gallons of water every two days to support the production of 2–5 large blooms weekly. I avoid soaker hoses because my watering routine is based on specific gallon measurements. It’s also important that dahlia tubers dry out slightly between waterings to prevent root rot.
Never spray water directly on the leaves, as this can encourage fungal diseases. Weekly pruning of spent blooms is essential—removing old flowers tells the plant to keep blooming instead of slowing production.
For more growing tips, check out my Dahlia Tips at the end of this post. And don’t miss the photos of some of my garden favorites—especially my number one: the radiant Yellow Kelvin Floodlight!
Betty Clark is a contributing writer. She has been an organic gardener since 1998. The signature flower she grows is Dahlias. She has a straw bale garden, a raised bed garden, and an in-ground garden. Both her surnames are from agricultural farming families (8 generations). Her hobbies include ancestry research, antiques, continued education classes, and workshops. She also has a background in marketing & promotions, including expos. To contact Betty Clark with gardening questions: bettyclark2151959@gmail.com
