Recommendations

In general, dahlias do not do as well in pots or containers as they do directly in the ground. If you choose to grow your dahlias in pots or containers, we recommend using the low growing or dwarf varieties of dahlias, as they are easier to maintain. However, any variety can be grown in a raised bed or container. When choosing a container be sure that there is adequate room for tuber growth. A dahlia could be easily planted in a 15" x 15" pot. For example, you could plant 3 full-size dahlias in a “whiskey barrel” sized pot due to the volume of soil. Raised beds should be a minimum of 12" deep to allow proper growth and drainage.

The planting medium should be 2/3 garden soil/topsoil to 1/3 potting soil or all garden soil. Potting soil alone is too porous, dries out too quickly and will cause poor growth and blooming results. Be sure that the potting soil and garden soil used are not chemically sterilized or treated with any type of weed killer or herbicide. Avoid potting soil that includes high nitrogen fertilizers, such as Miracle-Gro, compost, etc., as they will burn and rot the tubers. The difference in growing in containers rather than the ground is they will need water to start growing. Please make sure to keep your soil slightly damp, or cool to the touch after planting, not soaking wet. After planting and until you see the sprouts above the soil level, water sparingly, about once a week. Overwatering to keep the soil wet will result in rotting tubers.

The difference between growing in containers rather than on the ground is they will need water to start growing. Please make sure to keep your soil slightly damp or cool to the touch after planting, not soaking wet. After planting and until you see the sprouts above the soil level, water sparingly, about once a week. Overwatering to keep the soil wet will result in rotting tubers.

Once the dahlias have sprouted above the soil, water daily or as often as you would any other container plants. After plants are 12" high, potted dahlias will require extra watering and fertilizing to promote proper growth and blooming. We recommend fertilizing dahlias in containers and raised beds much more often than those planted directly in the ground, as the fertilizer is washed through the soil quicker.

Dahlias need to be watered consistently for proper growth and blooming. In containers we would suggest watering them 1 to 2 times per day once your dahlias are above the ground.

Fertilize approximately every 2–3 weeks with low nitrogen fertilizer or choose a slow-release fertilizer and follow the manufacturer’s recommendations. In raised beds you will water less often than in a container, however, more often than dahlias planted directly in the ground due to drainage. Fertilizing your dahlias in raised beds is similar to containers, applying it every 2–3 weeks.

Custom Blends | Highway Fuel is a local supplier that carries a soil mixture for dahlias that we recommend. Check out their blend.