How to Plant Dahlias
Dahlias, with their spectacular beauty, are a delightful addition to any garden. These showy blooms, ranging from one inch to a mammoth fourteen inches, grace your garden from midsummer until frost. With hundreds of varieties to choose from, most gardeners find dahlias a joy to grow.
Jump Ahead
Growing Dahlias from Tubers
Dahlias can be grown from tubers or seeds. If you purchase tubers, you plant them like daffodils or tulips. Be sure to wait until the weather is warmer and all threats of frost have passed before planting dahlia tubers. Planting too early will result in poor blossoms.
Where to Plant: Choosing the right spot for your dahlias is crucial. They need a location in your yard that receives at least six hours of sunlight daily. While they can thrive in any well-drained soil, they particularly excel in slightly acidic, sandy loam.
How to Plant: When planting your dahlias, remember that good airflow is essential for their growth. The spacing between your plants will depend on their variety and type. As a general guideline, small dahlia plants should be spaced a few feet apart, while larger varieties need three to four feet between plants and rows.
Dig a hole 6 inches deep and lay the tuber in the hole flat on its side. Cover with soil, followed by a thin layer of mulch. You do not need to water until the first sprout appears.
If you are planting large dahlia varieties that will require staking, place the stakes when you plant the tuber. Dahlia roots grow close to the surface and are fragile, so later staking could injure the plant.
Fertilizing: Dahlias benefit from high nitrogen fertilizer early in the season. Once the flower buds form, switch to a high-potassium fertilizer.
End of Season: In zone 7 and colder, dahlia tubers need to be dug up and brought inside at the end of the season. Warmer areas that include zone 8 and higher do not require digging up.
Starting Dahlia Seeds Indoors
In warmer hardiness zones, dahlia seeds can be sown directly into the garden beds where they will be grown. In more temperate zones, dahlia seeds should be started indoors.
When to plant seedlings indoors: You should start your seedlings 4-6 weeks before the last spring frost.
How to plant: Sow seeds in seedling trays or individual 4-inch pots about ¼ inch deep into the growing medium. Keep soil moist but not wet.
Germination temperature: 70 – 85 degrees Fahrenheit.
Days to emergence: 7 – 14 days
Planting prep: Once plants have been established, in about five weeks, they can be hardened for transplanting outdoors by bringing the plants outside on warmer days to acclimate them. Once all danger of frost has passed, they may be directly transplanted into your garden.
Tips for Dahlia Care
Proper care is key to the health and beauty of your dahlias. Regular and thorough watering, along with timely pinching back of new growth and deadheading, are essential practices. By following these care tips, you will enjoy their beauty all season long.
References
- Utah State University Extension – “Growing Dahlias.”
- University of Georgia Extension – “Dahlias.”
- Mississippi State University Extension – “Dahlia Care.”
- Colorado State University Extension – “Planting Dahlia Tubers.”
- Alamac – “How to Plant, Grow, and Care For Dahlias.”
- Cornell University – “Dahlia: Bedding Varieties.”
Related Products
