Growing Beautiful Dahlias
There is something magical about planting a little tuber in the ground and watching it become stunning flowers.
Dahlias are generous growers. Give them the right conditions, a little patience and regular picking, and they will reward you with an abundance of blooms from summer well into autumn.
Here’s everything you need to know to give your dahlias the very best start.
Keep them cool.
If your tubers have arrived before you're ready to plant, don't worry they're perfectly happy to rest for a little while. They can also look a little ugly but, we promise there is beauty inside!
Store them somewhere cool, dark, dry and well ventilated, away from direct sunlight, frost and heat.
A cupboard, shed or garage can work beautifully, provided it doesn't become hot or humid.
There is no need to soak your tubers before planting. In fact, keeping dormant tubers too wet can encourage rot.
It's normal for tubers to look a little dry or slightly shrivelled while dormant. They're simply waiting for the right conditions to grow.
When to Plant
Wait for warmth.
Dahlias don't love cold, wet soil. In Australia, the safest time to plant is generally spring, once the risk of frost has passed and the soil has warmed.
As a guide, look for:
- Soil temperatures around 15°C or warmer
- Frost-free conditions
- Consistently warming weather
- Soil that is moist but drains freely
For many gardens, this will fall somewhere between September and November, depending on your location and the season.
If you're unsure, wait a little longer. A warm start is far kinder to a dormant tuber than being planted too early into cold, wet ground.
Find sunshine.
Dahlias are sun lovers.
Choose a position that receives at least 6 hours of direct sunlight each day. Morning and afternoon sun are both wonderful, but the more light your plants receive, the better they'll generally flower.
Give them room to breathe, too. Good airflow around the plants helps create strong, healthy growth.
Planting time.
Once your soil is warm and you're ready to plant, it's time to tuck your tuber into the earth.
Place the tuber approximately 5–10 cm beneath the soil surface, with the eye facing upwards.
The eye is the small growing point where your new plant will emerge.
Give each plant around 40–60 cm of space, depending on the variety. Larger varieties will appreciate a little more room. Don't worry if your tuber doesn't look like much.
A dormant dahlia tuber can look surprisingly unimpressive. That's completely normal.
Inside that little bundle of roots is everything needed to grow an extraordinary plant.
Water with care.
One of the most common mistakes with newly planted dahlias is giving them too much water.
While the tuber is dormant, it doesn't need to be kept wet. Water lightly when planting, then allow the soil to dry somewhat until you see active growth.
Once shoots emerge, your watering routine changes.
As the plant grows, water deeply and consistently, particularly during warm and dry weather.
Water the soil around the base of the plant rather than keeping the foliage constantly wet.
Pinch them.
Want a bushier plant with more flowering stems?
When your dahlia is approximately 30–40 cm tall and has several sets of leaves, pinch out the growing tip.
This encourages the plant to branch rather than sending all its energy into one central stem.
More branches mean more opportunities for flowers.
Don’t forget to support them with a stake before they start growing for support.
Let them grow.
And Then… Let Them Grow
Dahlias don't need perfection.
They need sunshine, warm soil, good drainage, nourishment, water and a little patience and a lot of love.
Give them those things and they will do what dahlias do best grow, bloom and keep giving.
And the best part, the more you pick the more they grow!
We hope your garden is soon filled with them.
Happy growing!