How to plant dahlia tubers

How to plant dahlia tubers
dahlia flower arrangement
Dahlias are the perfect late summer and fall flower.

I’ve sold dahlia tubers the past couple of years as a way to supplement my winter income, as well as to share these amazing flowers with fellow dahlia lovers! It took me a while to figure out the best way to store them (and in fact, it’s a work in progress!) but as my stock of tubers has grown and I’ve gotten better at propagating them, I’ve found that sharing the love is the best way to go!

Some people are old hands at growing dahlias, but for those of you who might be new to them, here’s a short guide to planting:

  1. Plant at the right time of year. Dahlias like it warm, and if you plant too soon your tubers might freeze (and rot.) Always plant no sooner than the last predicted frost date in your area. My growing zone is 5b and my last frost date is May 15. I usually plant my tubers (outside) right around that date. I also pot some up ahead of time in order to propagate (this will be the subject of another post!) – and these pots are kept under lights or near a sunny window to stimulate growth.
  2. Once you’re ready to plant outside, choose a location: Dahlias thrive in well-draining soil with plenty of sunlight. Choose a location in your garden that receives at least six hours of direct sunlight per day and has good drainage.
  3. Prepare the soil: Loosen the soil to a depth of 12 inches and mix in some compost or well-rotted
    a la mode dahlia
    One of my favorites! A la Mode.

    manure to improve soil fertility and drainage.

  4. Plant the tubers: Dig a hole that is slightly larger than the size of the tuber and about 4-6 inches deep. Place the tuber in the hole with the “eyes” or growing points facing up. Cover the tuber with soil and water thoroughly.
  5. Water regularly: Keep the soil moist but not waterlogged until the dahlia sprouts. Once the plant is established, water deeply once a week or more frequently during hot, dry weather.
  6. Provide support: Dahlias can grow quite tall and may need support to keep them upright. You can use stakes or cages to support the plants.
  7. I don’t typically apply much fertilizer to my dahlia plants, but this will depend a lot on your soil health. If your plants appear to be flagging, apply a general “bloom-boosting” type fertilizer as directed.
  8. Dahlias will bloom late summer and fall. In my zone, with tubers planted mid-May, I’m guaranteed lots of gorgeous blooms in August.

With these steps, you should be able to plant and grow beautiful dahlias from tubers.