Dahlia Growing Guide 2026
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Katie’s TIPS for growing Dahlias
When you receive your Dahlia Tubers, you can keep them in their original packing until you are ready to plant outdoors. Keep them stored in temps 40-60ish degrees & away from any possible FREEZING temperatures. *You can get started early & pot them up indoors :)
1. Plant Tubers in the Spring, after your last Spring frost AND after your soil warms up to around 60 degrees. At the farm we use Mother’s Day as our “GO” time.
2.Planting Space: Dahlias need a SUNNY location (6+ hrs/day), They can be planted in the ground, OR in raised beds, OR in large pots OR even in grow bags. They will need fertile, well-draining soil to do their best!
3. Planting Depth & Distance: plant tuber horizontal, eyes up & 4-6” deep. Plant 12-18” from other plants. * PRO TIP: Add a small handful of Bone Meal to the planting hole soil. This is NOT a must, but can help you grow more blooms. Dahlias Tubers are heavy feeders, this helps feed the tuber
4. DO NOT WATER UNTIL the tuber has sprouted and leaves show above ground. Too much water before the tuber wakes up, and it becomes susceptible to rot. If your soil is really dry, water lightly.
5. WATER & Feed: Once your Dahlias have leaves showing, water consistently as they are heavy feeders. *PRO TIP: I use a Bloom Boost Fertizlier (low-nitrogen) every 2-3 weeks in season, to encourage more flowers. This is not a must, but can help grow more blooms.
6. Support: Some varieties benefit from being staked to hold them upright. Hortonova netting is helpful, or an extra tomato cage or corralling. Many people don’t stake the plant at all and their Dahilas grow just fine!
7. Cut & Come Again, the more you cut them, the more flowers they will grow! Cut the flowers, ENJOY and cut them again! If you are leaving blooms on the plant, deadhead spent blooms to encourage more flowers.
8. Dahlias take 90-120 days to bloom, depending on the variety, and your climate, when/how you start them, etc.. So be patient. You might get blooms in late July, or August or it might be early September. They will bloom, and keep blooming until the first frost. ENJOY every single Flower - they are so SPECIAL.
*KEEP IN MIND* These are TIPS that have helped me grow Dahlias at the farm the last 5 years. I learn something new EVERY YEAR. This guide may change slightly every growing season, just as I do. Cheers to enjoying the growing journey:)