How Not To Kill Your Dahlias
The title above ‘How not to kill your dahlias’ was suggested by a lovely person we met last week at RHS Hampton Court Flower Show. I thought it rather apt after all the conversations we had had with so many people who struggle a little to grow these rather wonderful flowers. The title is also very Ronseal (to those born after the internet, pop Ronseal into ChatGPT and it will explain…)
Being a bit of a dahlia nut and having grown them for over 10 years now, I take for granted that I know one end of a tuber from the other, how to deadhead, how to cut for cut stems and how to get these blooming gorgeous flowers going all the way through to the first frost. And then the big question of what to do with them over the winter: to lift or not to lift, that is the question. Whether it be nobler in the field…..
So here we are, the start of the flowering season and where I will post once a week (hopefully on a Friday in time for the weekend in your garden, but don’t hold me to that - Friday is one of our busiest cutting days…. But I am going to really try to stick to this) where I will share with you what’s going on at the farm in our dahlia field, all the tips and tricks for success and also to set up a community where you can ask questions and get answers to any problems you are facing - SLUGS I’m looking at you.
After I’ve covered the basics early on, the aim is to get more in depth in content so we will look at breeding, showing, conversations with the real dahlia pros - so for those of you that know your pinching from your potting, do stick around.
I’m going to have a crack at doing video updates, picture posts in between the Friday posts, and hopefully set up a space where everyone can ask questions, get help from each other or simply find that elusive dahlia that reminds you of your grandmother or loved friend.
But before all that, thank you to each and every one of you who bought a plant from us at Hampton Court. It was eye-wateringly expensive to get our little farm up to the big smoke and I thank you from the bottom of my heart for your support. The overwhelmingly positive reaction we received means so much to us and each and every conversation taught me so much about what people are interested in, the most common questions when it comes to growing dahlias and most endearingly, what a thoroughly lovely bunch of people gardeners are. Fellow dahlia nuts especially so.
Topics for 2025 and into 2026
Right, to business. Throughout the year there are specific times that dahlia jobs can be done and my posts will be centred around these times. So don’t worry about lifting your dahlias just yet, we will cover that according to the UK timeline round about October time. Planting, feeding, watering etc are more pressing questions so I will cover these imminently.
Below is a summary of the list of topics to be covered for the rest of 2025 but please do comment if you don’t see the particular topic you would like to know about and I’ll include it. If I don’t know the answer, I’ll find someone who does.
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Watering (particularly apt in the UK right now with a heatwave underway)
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Planting out
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Slug and pest control
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Feeding
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Pinching out - or ‘stopping’ as they say in the show world
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How to cut: cutting dahlias for optimal vase life vs deadheading
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The different classifications of dahlias (when what I think looks like a ball is actually a decorative…..and what that means for you)
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What makes a good cutting dahlia
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How to identify a spent flower from a bud
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Growing in peat free
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Lifting and storing vs leaving in the ground
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Where to buy your dahlia tubers
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How to multiply your stock through cuttings
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Collecting seed and breeding
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How to tell if dahlias are frost damaged
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What goes on at a dahlia show
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Chats with serious dahlia pros
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Common diseases and pests
What gives me the creds to write this and caveat
What you will read / see here will be my experience of growing dahlias here on our flower farm in the South Cotswolds, UK and producing potted dahlia plants for sale in our nursery. We are on heavy clay with mulched beds, planting into Myplex - sheets of black plastic which we burn holes through. Our main dahlia field holds 1,000 dahlias and is in full sun most of the day. Our nursery is also in full sun. I am a full time flower farmer but understand that for most, gardening is an enjoyable hobby but might only get attention a couple of hours a week.
I’ve been growing dahlias for over 10 years and have made all the mistakes as well as seen success - my dahlias have won classes at horticultural shows and our dahlia / cut flower display at RHS Hampton Court won Silver Gilt in July 2025. We are in our third commercial season on the flower farm and in high dahlia season, we cut on average about 1,000-1,500 dahlia stems a week so have handled a fair few of these beauties.
Having said all of that, every day is a learning day. There is still a huge amount for me to discover about these amazing flowers, SO if you disagree with anything you read or have a violent reaction to me or the flowers, PLEASE do message me direct rather than head over to a forum or somewhere off grid. Some people’s favourites are bright orange ball dahlias, some people’s are toffee toned waterlilies - like a personal preference on the flowers, I don’t believe there is one particular way to do things in gardening. It’s what works for you and I would really love to hear everyone else’s experiences. We all grow in different conditions and on different soil, and that’s what makes this growing community so completely wonderful.
First weekly post coming later on today. Please do hit subscribe if you want to join in our fab dahlia community here on Substack. And if you like what we are doing, do like the posts - it bumps us up the algorithm and we can share the dahlia love a little bit more.
Thanks so much
Rachel
