As you know, we both adore dahlias: sadly they don’t adore our garden. Dahlias appreciate a little elbow room and plenty of sunshine to grow well, neither of which they readily find at The Watch House. One recent garden visitor, pointing to Dahlia ‘Firepot’, exclaimed ‘everything looks so healthy …… apart from this poor thing!’. I might have been offended had I not agreed entirely: ‘Firepot’ looked sick and pale. It has taken me several years to come to terms with the changing conditions in our garden since I love to see those big, colourful blooms emerging from a mass of banana leaves. The truth is that behind those colourful blooms lie tall, straggly plants searching for the sun and often looking threadbare at the bottom.
Gaining an allotment gave us the opportunity to relocate and build our dahlia collection successfully. We started off with a dozen varieties overwintered as tubers, including ‘Honka Fragile’, ‘Verrone’s Obsidian’, ‘American Dawn’, ‘Nicholas’, ‘Firepot’ and ‘Bacardi’, all old favourites. To these we added another sixteen cultivars from Sarah Raven which arrived as tubers in mid March. Being unable to control ourselves we then went on to place an order for a dozen cuttings from the National Dahlia Collection in Cornwall. At no stage had we made any plans for where to put them all, either in the earlier stages of growth or later on. This is very much the way things happen here and I imagine in many other gardens around the world. Hence one dahlia bed at the allotment turned into four, plus a row of pots and perhaps another one to come ……
It’s been eye-opening comparing the performance of our dahlias on the allotments versus the garden, and observing those grown from cuttings rather than from tubers. You may have seen our live dahlia tour on Sunday, which illustrates how healthy and happy they are looking in their new home. (The quality of the video is poor to begin with but improves later on. Sadly allotments do not come with WIFI!)
Our allotment is bright and relatively exposed with free-draining, chalk soil. Our once lanky dahlias have grown stout and bushy thanks to several rounds of pinching out. This has resulted in them flowering a little later than anticipated, but they are more robust plants for it. The tubers we overwintered have made enormous, floriferous plants very quickly; one can spot the mature plants a mile off. But the dahlias grown from cuttings that didn’t arrive until early June have mostly caught up with with any tubers planted in March. Some are substantially bigger.
We prepared the ground well before planting, digging in well-rotted horse manure and adding a generous scattering of blood, fish and bone at the time of planting. Subsequently I have given an occasional liquid seaweed feed, but there’s probably ample goodness in the soil to see them through to the autumn.
So far we’ve kept on top of the deadheading. This will become a bigger chore as summer changes to autumn and our dahlias produce more blooms. Although better for pollinators, single dahlia flowers do not last long and need regular checking for spent blooms. I prefer to deadhead at the first sign of petals falling from the back of the flower – I have a real hatred of decay and disorder – whereas The Beau prefers to hang on and enjoy each bloom to the very last. Neither approach is wrong, the main thing is to stop the plant from producing seed and thinking it’s done its job.
As in most aspects of gardening we are novices, not experts. Growing sixty dahlias on an allotment is very different to growing a dozen in pots in the garden; what we’d really like is a field full of them. We are learning all the time. Pest control has been easier than we anticipated, thanks to a population of frogs we have recently discovered living under our shed. They have been chomping through a large proportion of the slugs and snails that typically frustrate gardeners’ attempts at growing dahlias. We had a very brief plague of black fly which was swiftly dealt with by a rescue squad of ladybirds. Rather than taking action with chemicals I am glad we waited to see what our little red friends could achieve. As for earwigs we watch and wait, but none so far.
Our support system is something of an experiment. Rather than staking each individual dahlia with a cane or post we have made a kind of framework using tree stakes and twine. I already regret using natural, cream-coloured sisal for the smaller beds as it is much too visible – you will see it clearly in some of the photographs. However green jute twine is easily snipped through whilst deadheading. Thanks to fine weather our dahlias have grown short and strong and we’ve had no wind or heavy rain to really test the efficacy of the framework. My hunch is that it could be a lot better, but it seems good enough for now. We’d love to receive tips from anyone who has to stake a lot of dahlias in a cost-conscious way.
As I write about 60% of our dahlias are blooming. The other 40% are dahlias grown from cuttings or acquired in early summer. These will start flowering by the end of the month, continuing into November if we are lucky. I have managed to post a ‘Dahlia of the Day’ on my Instagram account for over a month now, and hope to be able to continue for another month without repeating myself too often. Many of those images are repeated in this post, but if you’d like to see more, please give me a follow.
Dahlias are one of the most rewarding plants one can grow in a garden provided one can offer them the right conditions and are prepared to be vigilant when it comes to slugs and snails. They will flower for months on end, from June until the first frosts, never letting up. The number of cultivars runs into the tens of thousands with new introductions every year. Each country seems to have is own portfolio of dazzling dahlias so don’t be surprised if some of those I’ve mentioned are not available where you live.
Not all cultivars are good, but there are sufficient for you to find your own favourites. The only colour that does not feature in the dahlia colour palette is blue, and thank goodness for that! Dahlias will happily grow in pots provided they are well fed and watered. Although very far from being native, single-flowered dahlias are highly attractive to bees, supplying them with nourishment well into autumn.
If you’ve not grown dahlias before, or feel inspired to grow more next year, then early spring is the time to place your orders for tubers and rooted cuttings. If you happen to be in Cornwall, then a trip to the National Dahlia Collection at Varfell Farm is a must. You’ll be met with a 2 acre display of 1600 or more dahlias which will dazzle you with the sheer variety and brilliance of this dazzling flower family. TFG.