How To Grow Dahlias
Dahlias are absolute workhorses in the cutting garden. They are super easy to grow, so are great for beginners, and provide you with an abundance of flowers from about June through to the last frost. This year I was still cutting stems in November!! Dahlias like to be cut, so are great for bringing the outside in. In fact, the more you cut stems from dahlias, the more they will grow. I also love the huge variety of sizes, shapes and colours that you can buy. From single petal, to pom pom, all the way to huge dinner plate dahlias. There’s a few stages to growing dahlias, but we will be documenting it all here on the blog, so keep checking back to follow along with us.
When your dahlia tubers arrive, they will look like big, dry salamis. You can either keep them and plant them straight out into the garden in their final position when the last frost is passed. Or, you can pre-sprout them in a greenhouse a little earlier to get them big and strong before they go outside. I tend to go for the latter method, so that’s what I’ll share on here.
Get a large plant pot. It needs to be wide enough and deep enough for your tuber to fit in comfortably. Pop some compost in the bottom, put your dahlia tuber on top and then cover with more compost so it’s all tucked in. Dahlias are hungry plants, so a compost rich in nutrients is essential. Water, but don’t soak the compost as you could risk your tuber rotting.
We are waiting for the tuber to start sprouting. Soon you will start to see green shoots popping up through the soil. Watch out for slugs at this point as they love to chomp on fresh dahlia growth. Make sure that you don’t over-water at this stage, otherwise the tubers might rot!
2. After the last frost has passed, we can plant our dahlias outside. Before you plant them out, prepare the ground by adding some compost or well rotted manure. Dig a deep hole and plant your dahlia. Water well.
3. You dahlia will need some support as they grow to be large plants. There’s a few ways of doing this. You can use bamboo canes and twine to create a cat’s cradle style support around the plant. You can make a wire cage out of puppy mesh for the plants to grow through. Or if you are growing lots of dahlias all together, you can use jute netting pulled tightly across the bed for the dahlias to grow up through. If you don’t support your plants, they can easily getting pulled over by the wind and destroyed.
4. Watch out for slugs and other pests eating your dahlias at the early stage. We used wool pellets around the base of our plants last year as an organic deterrent and it seemed to work well.
5. When your dahlias have started flowering, make sure you deadhead them regularly and get stems often to encourage new growth. We will be doing a blog post about cutting and harvesting dahlias soon, so keep a look out!