Last year I grew some bedding dahlias from seed, they flowered nicely, although I should have dead headed them much more. Dahlias are tender perennials, prone to suffer a chilly end from frost and cold if not protected. I might be able to get away with leaving them in the ground with a thick mulch on top as we’re not in the Arctic north, but to be on the safe side I dug up the tubers for overwintering after the first frost. As much as anything else I wanted to see what was involved.
They’ve been hibernating in the shed, in a cardboard box full of compost and a coat of newspaper.
I should probably wait till March is well underway to start them off, but I’m keen to get some cuttings so I’m getting on with it, hoping that the greenhouse is pretty snug now with the heated bench acting like a big storage heater at night, must make a few degrees difference overall.
I’ve de-boxed them and checked them over for squidgy, potentially rotten parts, mostly they were fine, just 2 or 3 little pieces beginning to go over, they went in the bin. They are a peculiar looking bunch, dahlia tubers. Vaguely alien. Funny to think that these dangly articles started off less than 12 months ago as teeny seeds.
I’ve used the smallest pot in which the tubers fit snugly, some needed 3 litre pots, some just a tiny 7cm pot. They are buried so that the remains of the stem is just at the surface of the compost.
I have just used multipurpose compost, nothing fancy. At this time of year the tubers should just need contact with the damp compost to get the growth process going.
As I’m doing this sooner than I really should it could be several weeks before I see any signs of life. For now, I’ve just about got room in the heated propagator for the dahlia pots which hopefully will give them a nudge along, then I’ll move them out onto unheated staging when they start to show growth or when I need the space, whichever comes first!
I’m hoping that they put up some early shoots over the next few weeks that I can use for cuttings and thus get more plants. Each tuber should put on a few shoots that I can take and still plant the tubers out when they’re done. Apparently the cuttings taken this way produce more vigorous plants with more flowers. This is how the show growers get their mega blooms, so I’m told.
[update 27-03-17. Note, if you want to take cuttings, it’s best to leave the top of the tuber well clear of the compost. This is so that the cuttings can be easily taken and you can see what you’re doing. I discovered this the hard way when trying to take cuttings when the base was buried. See link just below for more details….]
I’ll be back, with news on growth, and setting out the cuttings.