DAHLIA GROW GUIDE

Congratulations on growing your own patch of Dahlias!

Dahlias are one of the most rewarding flowers which can be grown. From midsummer until autumn, they produce an abundance of spectacular blooms in almost every colour imaginable. Whether you're growing them for your garden, cutting patch or bouquets, a little preparation will reward you with months of flowers.

Before You Plant

Dahlias thrive in full sun. They are frost-tender, so wait until the danger of frost has passed before planting.

In most of Victoria, this is usually late September to late October.

If you're unsure, it's always better to plant slightly later than too early.

Choosing the Right Position

Dahlias perform best with:

At least 6–8 hours of direct sunlight
Well-drained soil
Protection from strong winds
Plenty of airflow between plants

Avoid areas that remain wet after rain.

Soil Preparation - Healthy soil produces healthy dahlias.

Before planting:

Add compost or well-rotted organic matter.
Work the soil to around 25–30 cm deep.
If your soil is heavy clay, improve drainage with compost and gypsum.
Avoid excessive fresh manure or high-nitrogen fertilisers.
Ideal soil pH is between 6.5 - 7.0

Planting Tubers

Depth - plant your tubers approximately 10-15cm deep with the eye facing upwards. Although this I recommended don't worry if you can't see the eye, the new shoot will find its way to the surface.

Spacing - for most varieties plant leaving a space of 45-60cm between plants. If you are growing in rows, leave 75-90cm between rows.

Watering - do not overwater immediately after planting. If the soil already contains moisture, wait until shoots emerge before watering regularly. Once actively growing, water deeply 1-2 times per week (more on very hot days). Water the soil and not the foliage.

Mulching - apply 5–8 cm of mulch once plants are established as this helps retain soil moisture and suppress weeds. Remember to keep the mulch away from the stems to avoid rot.

Fertilising - feed regularly throughout the season as dahlias are hungry plants. A balanced fertiliser or one slightly higher in potassium works well. Too much nitrogen will encourage foliage growth at the expense of flowers. A simple plan is to fertilise when plants are 30cm tall and then weekly.

Staking - many dahlias grow over 1 metre tall and require support. Install stakes at planting time to avoid damaging the tubers later. Either use netting as support or corralling.

Pinching Out - when plants reach approximately 30–40 cm tall, pinch out (remove) the growing tip above the 3rd or 4th pair of leaves to encourage bushier plants, stronger stems and significantly more flowers.

Pinch out the growing tip above the third or fourth pair of leaves.

This encourages:

Harvesting Flowers - harvest early in the morning or late in the evening, usually to avoid bees and to ensure flowers are well hydrated. Choose flowers that are fully open and firm at the centre. Unlike a lot of flowers, dahlias do not continue to open after cutting. Place them in water immediately.

Deadheading - remove spent flowers regularly. Deadheading encourages continuous flowering. Remember Dahlia are a cut-and-come-again type of plant s the more flowers you pick, the more you plant will produce.

Common Problems

Slugs and Snails - young shoots are particularly vulnerable. Protect emerging growth with your preferred control method.

Aphids - Usually controlled naturally by ladybirds and other beneficial insects. If required, wash off with water or use an appropriate insecticidal soap.

Powdery Mildew - Often appears late in the season. Reduce overcrowding and improve airflow. Avoid overhead watering.

End of Season

After the first frost blackens the foliage:

Cut stems back to approximately 10–15 cm.
Carefully lift the tubers.
Allow them to dry for several days.
Brush away excess soil.
Store in a cool, dry, frost-free location.

To learn more about dahlias or tuber storage, follow us on instagram and Facebook.

Enjoy the Season!

Dahlias reward gardeners with months of spectacular blooms, and every season teaches something new. Don't be afraid to experiment with varieties, colours and arrangements. With a little care, one tuber can produce hundreds of beautiful flowers throughout the growing season.

Happy growing!

The Petal Patch
Main Ridge, Victoria

DAHLIA GROW GUIDE

​

Congratulations on growing your own patch of Dahlias!

​

​

Before You Plant

​

Dahlias thrive in full sun. They are frost-tender, so wait until the danger of frost has passed before planting.

​

In most of Victoria, this is usually late September to late October.

​​

If you're unsure, it's always better to plant slightly later than too early.

​

Choosing the Right Position

Dahlias perform best with:

At least 6–8 hours of direct sunlight

Well-drained soil

Protection from strong winds

Plenty of airflow between plants

Avoid areas that remain wet after rain.

​

Soil Preparation - Healthy soil produces healthy dahlias.

​

Before planting:

Add compost or well-rotted organic matter.

Work the soil to around 25–30 cm deep.

If your soil is heavy clay, improve drainage with compost and gypsum.

Avoid excessive fresh manure or high-nitrogen fertilisers.

Ideal soil pH is between 6.5 - 7.0

​

Planting Tubers

​

Depth - plant your tubers approximately 10-15cm deep with the eye facing upwards. Although this I recommended don't worry if you can't see the eye, the new shoot will find its way to the surface.

​

​

Spacing - for most varieties plant leaving a space of 45-60cm between plants. If you are growing in rows, leave 75-90cm between rows.

​

Watering - do not overwater immediately after planting. If the soil already contains moisture, wait until shoots emerge before watering regularly. Once actively growing, water deeply 1-2 times per week (more on very hot days). Water the soil and not the foliage.

​

Mulching - apply 5–8 cm of mulch once plants are established as this helps retain soil moisture and suppress weeds. Remember to keep the mulch away from the stems to avoid rot.

​

Fertilising - feed regularly throughout the season as dahlias are hungry plants. A balanced fertiliser or one slightly higher in potassium works well. Too much nitrogen will encourage foliage growth at the expense of flowers. A simple plan is to fertilise when plants are 30cm tall and then weekly.

​

Staking - many dahlias grow over 1 metre tall and require support. Install stakes at planting time to avoid damaging the tubers later. Either use netting as support or corralling.

​

Pinching Out - when plants reach approximately 30–40 cm tall, pinch out (remove) the growing tip above the 3rd or 4th pair of leaves to encourage bushier plants, stronger stems and significantly more flowers.

Pinch out the growing tip above the third or fourth pair of leaves.

This encourages:

​​

​

Deadheading - remove spent flowers regularly. Deadheading encourages continuous flowering. Remember Dahlia are a cut-and-come-again type of plant s the more flowers you pick, the more you plant will produce.

​

​

Common Problems

​

Slugs and Snails - young shoots are particularly vulnerable. Protect emerging growth with your preferred control method.

Aphids - Usually controlled naturally by ladybirds and other beneficial insects. If required, wash off with water or use an appropriate insecticidal soap.

​

Powdery Mildew - Often appears late in the season. Reduce overcrowding and improve airflow. Avoid overhead watering.

End of Season

After the first frost blackens the foliage:

Cut stems back to approximately 10–15 cm.

Carefully lift the tubers.

Allow them to dry for several days.

Brush away excess soil.

Store in a cool, dry, frost-free location.

To learn more about dahlias or tuber storage, follow us on instagram and Facebook.

Enjoy the Season!

Dahlias reward gardeners with months of spectacular blooms, and every season teaches something new. Don't be afraid to experiment with varieties, colours and arrangements. With a little care, one tuber can produce hundreds of beautiful flowers throughout the growing season.

Happy growing!

The Petal Patch Main Ridge, Victoria

The Petal Patch
Main Ridge, Victoria