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Dahlia flowers by Margaret Alston

Dazzling dahlias – how to pot them up!

Large colourful dahlia flowers against a backdrop of greenery

By Margaret Alston, ‘newbie dahlia enthusiast!’

Dahlias to me were always something other gardeners grew and were not for me! I thought they might be difficult and problematic perhaps, and I maybe even thought that they would not attract bumblebees. However, my mind has been changed after visiting beautiful National Trust gardens late last summer, where dahlias and bumblebees were plentiful. I have since then paid more attention to this, what now appears to be, fantastic long-flowering beauty. I have decided to give dahlias a chance in our garden this year and ‘Bee the Change’.


First of all, I needed to select which dahlias I would grow, and although you can grow dahlias from seed, I decided that tubers would be best for a beginner like me!

Selection was a bit of a minefield with no end of varieties and types. Bumblebees seem to love single-flowered dahlias, but also collarettes (with their tiny frilled collars) and anemone-flowering varieties (with their central ‘pincushions’) seem popular. They also vary greatly in height from maybe 40cm to well over a metre, with many that can be grown in pots. So, all in all, a great choice out there for flower and bumblebee lovers like me.

Bee the Change top tip! Look for dahlia varieties where the pollen is visible in the centre of the flower and not hidden by lots of dense petals. These are best for bumblebees and other pollinators.

I chose and ordered a variety of tubers to try out, mostly just one of each, which included all the above named types. While waiting for them to arrive, I prepared my pots … a selection of 2 or 3 litre ones, reused from garden centres, which I thoroughly scrubbed. At the garden centre, I chose some multi-purpose peat-free compost as the best option for the environment, and used it straight from the bag with no need to make up a mixture!

Once the tubers arrived I laid them out and wrote labels for each. The tubers vary greatly in size so the different sized pots are useful as the tuber needs to fit quite snugly in its pot. I filled each pot about a third with compost, then placed a tuber in and added more compost until only the old stalk was showing. It doesn’t matter if the stalk is not sitting centrally as it tends to move to the side itself!

I then put my pots into my unheated greenhouse and watered sparingly, according to instructions. I will continue to water every few days to make sure the compost stays damp.

Hopefully the tubers will sprout leaves and the dahlias will be ready to plant out in my garden by mid to end of May. My intention is to put them all into larger pots but we shall see… Follow me on Twitter @bumblebuddeez for regular updates or stay tuned for an update on my dahlias here!

Thank you for reading my blog and hopefully some of you will join me on my dahlia growing journey!


June update

After potting up my dahlia tubers in March, I thought that they might take perhaps a couple of weeks to sprout, but in fact they took several weeks! I visited them daily, anxiously watching for tiny signs of life. They seemed very dry… should I water them? I read that if they were watered too much, the roots would rot. In the end, I sparingly watered them sometimes, but still there were no signs of life!

Then, after seven weeks, just when I was giving up hope, I was relieved to see a tiny shoot. After that they gradually sprouted one by one… what delight with each new ‘birth’!

Now after ten weeks, I had some which seemed ready to put into their final position. Many people plant them straight into the garden but I had decided because of a munching snail problem to put them into containers.

Advice is usually to pot them into fairly large, maybe 20 litre, containers, but thinking about the amount of compost that would take, I decided to gather my larger containers and pot my dahlias according to size. For example, the single flowered ones should grow to about 45cm so would go into slightly smaller pots, while some of the collarette varieties I chose could grow to nearly a metre, so they would go into larger pots.

My peat-free compost mixture consisted of ‘multi purpose’ plus ‘mature plant’ with some perlite. In the bottom of the pots I put polystyrene pieces of old packaging or crocks then I potted up four of my precious plants. I will pot up the rest gradually over the next couple of weeks.

Now, coming back to this slug and snail problem. As my garden is completely organic and I rely on nature to create its own ecosystem, sometimes a helping hand is needed. Slugs and snails love to eat dahlias and so a barrier is necessary. I have tried various things but these organic barrier pellets (which they hate to walk over) plus copper tape round the pot, hopefully will do the trick! I have also tried wool pellets and have heard that holly leaves work well.

Now all I need to do is wait for my dahlias to flower – I can’t wait to see which varieties the bumblebees like most! Happy planting everyone!


September update

What a summer it has been… dahlias have certainly dazzled! After planting into pots at the end of May, just over a month later, at the beginning of July, they started to bloom, slowly at first then blooms and bumblebees came thick and fast.

I kept all the pots together on a ‘dahlia theatre’, an old lofty table that slugs and snails did not reach, to begin with, but as the season progressed I did place them among my borders when a space appeared.

As well as the ten tubers that I had planted into large containers, I also planted some seeds which quickly and easily germinated and were soon ready to plant out. Again, I put them into pots, out of reach of munching snails and they also started to bloom. I kept them all very well watered and fed them every couple of weeks with liquid seaweed.

My anemone flowering dahlias were beautiful but because of rather frilly and fussy centres, not so appealing to bumblebees, with one exception: ‘Totally Tangerine’, a beautiful long-flowering and bumblebee-attracting plant. For some reason, bumblebees just love it!

My collarette dahlias, ‘Kelsey Annie Joy’ and ‘Fashion Monger’ both performed extremely well, continue to flourish now, and have attracted many bumblebees. They are so beautiful with their little frilly skirts. I shall be treating myself to other varieties from this group next season.

The two single-flowered dahlias I grew from tubers, ‘Wishes and Dreams’ and ‘Happy Single Kiss’, again have been exemplary in their behaviour. They have bloomed and bloomed providing much food and resting places for bumblebees.

One thing that has been such a joy is a little packet of dahlia seeds, harvested then sent to me from a ‘Twitter friend’, Dotty’s garden. They were easy to grow and it was fun to wonder what colours/shapes would appear. I have constantly been deadheading all my dahlias but have now left some seed heads so that I may follow Dotty’s example by collecting and storing seeds for next year. I called my mixture ‘Dotty’s Dahlias’.

Many of my dahlias are still flowering and giving joy to anyone who visits my garden and the last few hungry bumblebees, striving to find the last drops of nectar. My ‘Dazzling Dahlias’ as I like to call them have been a success and I am hooked. I will attempt to store some of my tubers over winter, gather seeds, and I know in spring when gardening catalogues appear, I shall be choosing more… I already have a list of favourites!

Check out more planting guides and resources with our Bee the change campaign here.