Written by Megan Haworth of Pink Sky Flowers Co, a Harleysville PA based flower farm specializing in dahlias. Follow her beautiful journey on Instagram at @pinkskyflowersco

Have you been drooling over gorgeous dahlia photos online, wondering if you could grow them yourself? The short answer: YES! While dahlias have specific needs to thrive, they’re attainable for beginner to intermediate gardeners. In fact, I often tell people, “If you can grow a tomato plant, you can grow a dahlia!” Their requirements are surprisingly similar.

The Basics

Dahlias hail from the mountains of Mexico but have been hybridized into the blousy, fully double blooms commonly seen today. They’re typically grown from tubers—or more technically, tuberous roots—rather than from seeds. Although you can find dahlia tubers at big box stores, choosing American-grown tubers usually means starting with better quality: more hydrated and less prone to disease.

Planting

Plant your tubers in spring after your last frost date—around Mother’s Day in the Philadelphia Area, zone 7a. Select a site with full sun (at least six hours daily). Dig a hole 4 to 6 inches deep, place the tuber horizontally, as if you're putting it to bed, and cover it with soil. If the soil is dry, water lightly, but if spring rains have kept the soil moist, you may not need to water at planting.

In the landscape garden, space dahlias 18 to 24 inches apart to ensure good airflow. Larger varieties may need the full 24 inches. As a flower farmer growing for production, I often plant my dahlias even closer at 12 to 18 inches, as I will be harvesting them regularly and cutting them hard!

Staking

Place a strong support, such as a metal T-post, wooden stake, or tomato cage, at planting time. This prevents damaging your tuber later when installing supports. As the plant grows, gently tie it to the stake to help it stay upright. Many dahlia varieties will grow to be as tall as 5 to 6 feet in height, so do not skip this step!

Soil and Watering

Dahlias thrive in rich, well-drained soil. Improve your soil by adding organic matter such as compost, leaf mold, or mushroom soil to the surface when you plant. This layer of organic mulch also helps with weed prevention and will eventually be mixed into the soil by earthworms and other beneficial soil organisms.

After planting, dahlias may take 2 to 4 weeks to emerge. Resist the urge to overwater during this time—too much moisture can cause tubers to rot. In most cases, late spring rainfall provides enough water. Once the green leaves emerge, ensure the plants receive about an inch of water per week, either from rainfall or supplemental watering.

Maintenance

Keep the area around your dahlias weed-free, especially while the plants are young and small. This prevents weeds from competing for water and sunlight. As dahlias grow taller, their foliage will naturally shade out most weeds, reducing the need for constant weeding.

When the plant reaches about 12 inches tall, you can pinch out the top set of leaves to encourage bushier growth and more blooms. This step is optional, but can greatly increase the number of flowers the plant will produce!

Bloom Time and Harvesting

Dahlias bloom from late summer until the first frost. The more flowers you cut, the more your plant will produce! Don’t be afraid to cut stems deep into the plant when harvesting to bring inside—this encourages fresh buds to grow.

Consider yourself warned—once you start growing dahlias, it’s hard to stop! With thousands of cultivars to choose from, there will always be another one to drool over.

Written by Megan Haworth of Pink Sky Flowers Co. @pinkskyflowersco