Photography: Alice Veysey
Madeleine Lambert is living the dream, or at least, the dream of many ambitious, beginner gardeners. Since returning from a stint in Bangkok, Thailand, she and her family settled into an old kiwifruit orchard on the edge of Bethlehem, Tauranga. Amid the busyness of Covid (Madeleine is the assistant head of secondary at a local school), she found joy and stillness among her flowers.
“In my garden, I have learnt to breathe again, to take in the beauty and wonder of it all… One of my greatest pleasures is my morning, dressing gown clad, wandering among the flower beds,” she says.
Since receiving a bouquet of pom pom dahlias as a birthday gift, Madeleine was inspired to grow her own, and better yet, create bouquets to give to friends and family. In 2021, she started her very own picking garden, which quickly expanded thanks to her husband’s support (and generous labour). Madeleine read, researched, watched YouTube tutorials, and spoke to experts, all in pursuit of learning to grow various dahlia varieties alongside a plethora of other plants and flowers.
In 2023, Madeleine launched Petal & Twine, so others can order her bouquets as one-offs, for events, or on a subscription basis, a venture she describes as a “passion project”.
“My garden, and growing flowers, have been so nourishing, healing in so many ways. I am so blessed to bring joy to others, supplying fresh blooms and bouquets”.
Today, Madeleine is what we’d call (she’s too humble to admit it) an expert in growing dahlias, and luckily, she’s incredibly happy to share her knowledge.
Dahlias are known for their stunning variety. How do you choose which varieties to grow each season?
Colour is always where I start — I’m drawn to soft whites, blush pinks, and pale pastels, as well as warm terracottas, and rich jewel and antique tones. I think about how each variety will work both in bouquets and out in the garden. I also consider shape and texture — I grow a mix of pom pom and ball dahlias like Cornel Bronze, bold dinner plates like Penhill Watermelon, cactus and decorative types, and a few playful forms like Honka Fragile.
That said, my favourite is probably Bowen, also known as Small World — a tiny white pom pom, sometimes kissed with the faintest blush and deep cerise tips that show up when it’s blemished. It reminds me of kintsugi, the Japanese art of repairing broken pottery with gold. There’s something really beautiful about that.
Dahlias die back when temperatures drop and daylight hours shorten, but because they grow from tubers, they come back year after year, as long as you take good care of them. Every winter, when tubers come out for sale, I seem to “acquire” more and more… there are just so many beautiful varieties to add to my ever-growing collection!
Can you share your process of storing and planting dahlia tubers? And how do you prepare your garden for spring?
Dahlia tubers are frost-tender and can rot over winter, especially in heavy or waterlogged soils. Many growers lift their tubers before the first frost, then clean, dry, and label them (trust me, you will forget which is which!). Tubers can be stored in a cool, dark place, nestled in wood shavings, sawdust, or dry potting mix.
Winter is also a great time to enrich the garden beds — I add compost, sheep pellets, a sprinkle of blood and bone, and a thick layer of mulch to give the soil a good boost before spring.
Here in the Bay of Plenty, especially in our sheltered spot, frosts are rare and the soil drains well, so I mostly leave my tubers in the ground. The only time I dig them up is when I want to move or divide clumps, which naturally multiply during the season — great for sharing with friends.
Once the threat of frost has passed and the soil has warmed (usually mid-spring, depending on where you live), I plant the tubers about 10cm deep with a bit of bulb food, making sure the ‘eyes’ face up. I don’t water until green shoots appear — this helps avoid rot.
Are there any key steps to growing a successful dahlia garden? Did you make any mistakes starting out?
So many! At first, I really didn’t know anything about tubers. They look a bit like shrivelled kūmara. Each healthy tuber has three parts: the body, the neck, and the crown, where shoots form from small bumps called ‘eyes’. I definitely planted a few broken-neck, crown-less, or eye-less tubers my first year and spent weeks wondering why nothing sprouted!
I also didn’t realise how big and top-heavy dahlias get. Some of my largest grew nearly 6 feet tall! A storm flattened many plants in my first season because I hadn’t staked them. I quickly learned staking is a must — even a few bamboo canes, hardwood stakes, or waratahs intertwined with string will do. Dahlias grow so fast that they soon hide the supports. But you learn as you go.
Here are my best tips:
Pick a sunny spot — dahlias need at least 6 hours of full sun daily.
- Improve your soil with compost and add bulb food when planting.
- Wait until after the last frost before planting tubers.
- Space tubers no closer than 40cm to allow for airflow and healthy growth.
- Pinch early — when your plant has 3–4 sets of leaves, pinch back to the second set to encourage branching (more stems = more flowers).
- Stake early — don’t wait until plants are tall and heavy.
- Strip the bottom 20–30cm of leaves once the plants are established — this helps improve airflow and lowers the risk of powdery mildew forming on the foliage.
- Water wisely — dahlias originate from the hot, dry climates of Mexico, so they’re not super thirsty. Deep, occasional watering during dry spells (preferably in the evening) keeps them healthy. Mulch well to retain moisture.
- Feed later in the season with diluted fish or seaweed fertiliser to keep blooms pumping.
- Pick often and deep — the more you cut, the more they bloom, and longer stems make better bouquets.
- Don’t be shy about asking questions — gardeners are amongst the most generous people I know. I’ve learned so much just by chatting with horticulture teacher friends, local garden centre staff, and fellow flower lovers. There’s even a dahlia Facebook group full of friendly, knowledgeable growers who are always happy to help.
What’s the best low-maintenance but high-impact dahlia you’d recommend for beginners?
Ball dahlias are ideal, reliable, and productive — plus, they last well in the vase and look stunning in the garden. Their neat, symmetrical shape stands out with minimal fuss.
Some of my favourite beginner-friendly ball dahlias are:
- Petra’s Wedding — crisp white and elegant
- Sweet Nathalie — soft blush with a romantic feel
- Caitlin’s Joy — a smoky magenta that almost glows
- Brown Sugar — warm, spicy tones that live up to the name
There’s a ball dahlia in almost every colour, so pick your favourite and get started. Once you grow one, you’ll be hooked!
Do you grow companion plants with your dahlias?
Absolutely. I love a garden that feels full and alive, bursting with texture and colour. I plant Cosmos, Zinnias, Celosia, Ammi, Yarrow, Sunflowers, Statice, Bupleurum, and Bells of Ireland among and between the Dahlia rows.
These companions attract pollinators, soften the bed structure, and add movement and lightness. They’re also fantastic bouquet fillers, adding airiness, contrast, and visual interest to every arrangement.
What is one dahlia variety every gardener should try at least once?
I’d say Café au Lait — a generous dinner plate dahlia. Creamy, romantic, and impressive in size, it always stands out in the garden and bouquet. Honestly, I still think it truly deserves the hype it’s earned through NZ’s dahlia growing renaissance.
I also adore Burlesca — a smaller ball dahlia with dreamy ombré shades of pink, peach, and coral. It blends effortlessly with almost any colour palette.
And Boom Boom White is another must-grow — a large, pure white ball dahlia with the strongest stems and incredible productivity. It’s reliable, long-lasting, and incredibly useful in both garden beds and cut flower work.
Happy gardening and growing joy!
See more of Madeleine’s garden in full bloom, and order your flowers via her Instagram or Facebook.
