Why Start Indoors?
Starting dahlias in pots was a real turning point for me. It gave me a head start on the season and meant I could keep a closer eye on them in those early weeks.
I usually pot mine up in early spring, most often in March. The exact timing depends on how warm and bright your space is, but March tends to be a good balance. Early enough to get going, without risking cold, slow growth.
How to Pot up Tubers
I use a good quality compost and always mix in perlite to help with drainage. Dahlias hate sitting in wet soil, especially before they have started growing, so this step makes a big difference.
I pot each tuber into a 21 centimetre wide pot. This size gives the tuber enough space to grow comfortably without the compost staying cold and wet for too long. Bigger is not always better at this stage.
I plant the tuber upright with the eye facing upwards, just below the surface of the compost. I do not bury it deeply at this stage. I keep the pots in my conservatory, where they get plenty of light and stay frost free.
Encouraging More Flowers
Once the plant has a few sets of leaves, I pinch out the main stem. This means chopping off the top of the plant at a leaf joint. It can feel harsh the first time you do it, but it encourages two side shoots to grow instead of one main stem. More stems means more flowers later on.
Watering is light at first. Until shoots appear, I am careful not to overdo it. Once I see green growth pushing through, I gradually increase watering and let the plant take the lead.
That first sign of life always feels like the real start of the season. From that point on, everything feels possible again.
My Planting Essentials
