Growing Dahlias
Native to Mexico, dahlias delight in many forms and colours. From the tiny pompoms, exotic cacti and lotus, to the spectacular dinner plate varieties, it doesn’t take long for dahlia growing and collecting to become an obsession.
Ashburton Community Garden member Hanna is sharing her experiences of growing dahlias.
My husband Al and I have found our passion for dahlia growing over the past five years or so. Like any gardeners, we have learned just as much from our failures as from our successes! I will include a list of resources below from the official experts, but here is our journey to happy dahlia growing.
Where do I begin?
Life for a dahlia begins with a tuber. It’s incredible that such things of beauty grow from a nugetty tuber like a small sweet potato. You can purchase tubers from all the usual sorts of places, but the real fun comes from flower farms - where tuber procurement is nearly a blood sport! Coveted varieties sell out within minutes, and you need a wishlist and quick fingers for your online purchase. Tubers usually sell from September after farms have lifted and divided them over the winter.
A couple of my favourite farms for tubers are:
Florelie (excellent for dahlia growing tips too!)
Storage
Keep your tubers in a nice dark place until you are ready to plant. There are different schools of thought around how to store your dahlia tubers, and you can experiment to find the best method for you. After some trial and error with sawdust and shredded newspaper, the method that works best for us is storing tubers in vermiculite in plastic storage boxes with holes drilled.
You do not need to worry about this for your first season! Keep the tuber in the bag it arrives in, and store somewhere dark and cosy.
Planting
Traditionally it’s said to plant your dahlias two weeks either side of Cup Day. I like to give mine a head start, and start my tubers in pots in a warm, sheltered place in my backyard. I usually start them in early October. It’s important not to plant them out until the threat of frost has passed. Also note that ideally you are not to water your tubers until the stem and first leaves appear, as tubers can be prone to rotting. However if you get some rain, don’t panic! I’ve even started my pots in a warm room upstairs, but it’s now my baby’s bedroom, so that level of dahlia mania may have to stay in my past.
Dahlias are heavy feeders, so prepare your soil in advance.
We have experimented with many different staking methods. When starting out, the simplest is just to have a single stake per tuber. Pop the stake in as you plant, to avoid piercing the tuber later. I will share alternative methods in a later post. This will be more relevant when you are mass planting a bed.
Be sure to add a plant marker your plants as you pop them in so that you remember the variety! I still have a mystery dahlia that is prolific, but the name has long been lost.
Grow you good things!
For more information:
Check out these experts on social media or via their websites and books below
Floret Farm has a fabulous library of information on growing dahlias, but even better, Erin has written a bible on the topic!
Florelie shares a lot of knowledge on her website, but her Instagram page is a goldmine for dahlia know-how!
Dahlia Society of Victoria has a wealth of knowledge. As above, the website is a fantastic resource, and they publish monthly guides for dahlia care.