Dahlias are beautiful, full-blooming natives of Mexico that can be grown virtually anywhere in the summer. Planting dahlias in containers is a great choice for people who have little space for a garden. Even if you have a garden, a container grown dahlia can live on your patio or front porch, bringing those gorgeous blossoms up close and personal. Keep reading to learn how to grow dahlias in containers.
Can Dahlias Be Grown in Containers?
Can dahlias be grown in containers? Yes, but it’s a little bit of a process. If you want a bulb you can plant and forget, you may want to pick a different plant.
Choose a container that’s big enough in diameter that the tuber can fit comfortably when laid horizontally in the bottom. Just-planted dahlias tubers are at risk of rotting, so make sure your container has plenty of drainage. If it only has one or two holes, consider drilling a couple more.
Moisten a very loose potting mix that contains good draining elements like perlite and bark, and fill the container about a third of the way up. Lay your tuber flat in the container with the eye or sprout, if there is one, facing upwards. Add more potting mix until the tuber is just barely covered and the eye is just sticking out.
Care for dahlias in pots includes giving them support as they grow taller. Next to the tuber, sink a strong pole up to 5 feet (1 m.) in length to the bottom of the pot. Drill two holes into the side of the pot opposite the pole, and anchor it in place with a piece of wire or string. Placing the support pole at this stage saves the roots from being damaged in the future.
Planting dahlias in containers requires some maintenance at this stage. If you’ve started it inside, which is recommended in areas with short growing seasons, put your container grown dahlia directly under a grow light set to a 12 hour timer.
Keep track of the plant as it grows and lightly fill in more potting mix around it as it grows up. Keep doing this until you reach 1 inch (2.5 cm.) below the top of the container.
How to Grow Dahlias in Containers
Care for dahlias in pots, once you’ve filled the container with potting mix, is not too hard. Place them outside when the weather warms in a place that receives full sun and water and fertilize them regularly.
As your container grown dahlia gets taller, tie it to the stake and pinch off the top to encourage bushy growth to the sides.