Growing Dahlias in Victoria
Dahlias are one of the most rewarding flowers to grow in the Victorian garden. From early summer through to the first autumn frost they produce armfuls of colour, feeding bees, brightening borders and filling the house with flowers.
All of the dahlias offered through Thistle & Weeds are grown and trialled on our small flower farm in the Dandenong Ranges. The advice below reflects how we grow them here in our local climate.
When to Plant Dahlias in Victoria
In Victoria dahlias should be planted once the risk of frost has passed and the soil begins to warm.
For most gardens this falls between:
Late September and early November
Planting too early in cold soil can cause tubers to rot before they sprout. If in doubt, wait until daytime temperatures are consistently mild (at or above 15c).
Choosing the Right Spot
Dahlias thrive in a sunny position with fertile, well drained soil.
For best results choose a location that receives:
• At least 6 hours of sunlight per day
• Good air movement
• Soil enriched with compost or organic matter
Avoid heavy clay soils that stay wet in winter.
How to Plant Dahlia Tubers
Plant tubers horizontally in the soil with the growing eye facing upward. I like to add a sprinkle of Fish N Bone at the time of planting.
Space tubers roughly 40-50cm apart to allow them room to grow.
Cover the tuber with about 10cm of good quality soil (I like to use Clyde compost), top dress with mulch and water in lightly.
Supporting Tall Dahlias
Many dahlias grow over one metre tall and benefit from support.
Common options include:
• Bamboo stakes
• Tomato cages
• Garden netting stretched across beds
Adding support early prevents stems from snapping in wind or heavy rain.
Feeding and Caring for Dahlias
Dahlias are hungry plants and respond well to rich soil.
We recommend:
• Compost added before planting
• A balanced organic fertiliser during the growing season (NPK)
• Regular watering during hot weather
Pinching the growing tip when plants reach around 30 cm tall encourages branching and produces more flowers.
Cutting Dahlias for the Vase
Regular cutting encourages dahlias to produce more blooms.
Harvest stems when flowers are fully open and the backs of the petals feel firm.
Cut early in the morning and place immediately into clean water.
Many varieties grown on our farm are selected for their performance as cut flowers, producing long stems and repeat blooms through the season.
Lifting and Storing Dahlia Tubers
In colder parts of Victoria gardeners often lift tubers after the first frost.
1
Cut the plant back to about 10 cm above soil level.
2
Carefully lift the tuber clump with a fork.
3
Allow soil to dry and gently brush it away
4
Store in a cool, dry place over winter (like a garage) in clean soil.
Choosing Dahlias for your garden
There are thousands of dahlia varieties, each with its own colour and form.
At Thistle & Weeds we focus on varieties that offer:
• strong garden performance
• beautiful cut flowers
• distinctive colours and forms
Many are the same cultivars we grow in our fields for floral design.
Dahlia tubers grown in the dandenong ranges
Every tuber we offer is grown on our farm in the Dandenong Ranges and harvested at the end of the season.
Our collection includes florist favourites, garden classics and a small number of rare varieties that are propagated here each year.
an open invitation
There’s always more happening here than what fits on a page. If you’d like to see the garden as it changes, the flowers as they’re gathered and the quiet moments behind each arrangement, you’re warmly invited to join us over on Instagram.
Contact Us
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We usually respond within one business day. Be sure to check out our FAQs if you have any questions.
what makes us different?
SLOW-GROWN, FARM TO VASE
Every flower we use is grown on our boutique farm in the Dandenong Ranges. We harvest by hand, in rhythm with the seasons, and design the same day - no cold freight, no middlemen. Just nature, at her most generous.
A Little Wild, a Little Like You
We honour the unruliness of nature and the people who love it. Our arrangements are sculptural, seasonal, and a little uncontained. Each one is an artistic celebration of what’s blooming now.
Luxury, Rooted in Intention
Luxury, to us, is about presence; in the growing, the gathering, and the giving. Every order is wrapped with care in compostable materials, tied with our signature ribbon, and accompanied by a handwritten card.
Flowers You Can’t Get Anywhere Else
We grow varieties that don’t survive shipping or shelf life - fragile, fleeting, beautiful things. Harvested to order. Designed just for you. That’s why you won’t find our flowers in any shop window.