National Dahlia Society of New Zealand

Blue Bayou Precocious Annamari Oreti Rebel Claire de Lune

Cultivation Notes

For more detailed information join your local Dahlia Society. They will be only too happy to provide information suitable to your local area and conditions.

Where to Plant Dahlias

The area to be planted should receive at least 3 or 4 hours of full sunlight and have protection from prevailing winds. Dahlias will grow in almost any soil, but prefer well drained loamy soil conditions.

Cultivation and Planting

  1. Deeply cultivate ( ideally the area should be dug over several weeks before planting )
  2. Add a little compost if available. Avoid raw or very rich animal manure, (a little may be OK but too much can cause excessive soft growth. Plants with soft stems are more likely to break or be susceptible to diseases like mildew or stem rot.
  3. Add a dressing of well balanced garden fertilizer to manufacturers recommendations ( best applied 10 to 14 days before planting )
  4. Firm in a strong stake before planting ( staking after planting damages roots and tubers ).
  5. Plant tuber 10 to 12 cm deep, raise shoot end 5 to 6 cm below the surface. ( Planting on an angle allows excess water to drain off the tuber avoiding rot ) Plant pot tubers 10 to 12cm deep.


When plant growth has reached approximately 20 cm ( 8 inches ) it is important to pinch out the centre or the growing point, this encourages branching and more flowers.


When the plant reaches 30 to 45 cm high ( 12 inches ) apply the first tie. At least two further ties will be required during the growing and flowering season.