Dahlia White

Dahlia ‘White’ is a timeless favourite, bringing a fresh, bright look to borders and patio pots from midsummer right through to the first frosts. The blooms open in clean, classic white tones, adding elegance to any planting scheme and helping to “lift” mixed borders—especially when paired with richer colours. White dahlias are also brilliant in evening gardens, as the flowers seem to glow as the light fades.

It’s a wonderful cut flower too. White blooms work with absolutely everything in a vase, and regular picking (or deadheading) encourages the plant to keep producing new flowers for months.

Planting Instructions

When to Plant:

Plant Dahlia tubers in spring. For the earliest flowers, start tubers in pots indoors from March to April, then plant out once the risk of frost has passed. If planting directly outside, wait until late spring when the soil has warmed.

Where to Plant:
Choose a sunny, sheltered position with fertile, well-drained soil. Dahlias are ideal for mixed borders, cutting gardens and patio containers. They love warmth and perform best in full sun.

How to Plant:

• Depth: Plant tubers about 10–15 cm (4–6 inches) deep, with the old stem (or growing point) facing upwards.
• Spacing: Space plants 45–60 cm (18–24 inches) apart, depending on the final size.
• Soil Prep: Enrich the planting area with well-rotted compost or manure. In heavy soil, improve drainage with grit.

Watering:
Water after planting. Once shoots appear and growth is underway, keep soil evenly moist, especially in dry spells. Avoid waterlogging. Container-grown Dahlias may need watering daily in hot weather.

Aftercare Tips:

• Pinch out the growing tip once plants are around 30 cm tall to encourage bushier growth and more flowers.
• Stake taller stems if needed, especially in exposed borders.
• Deadhead regularly (or cut for the vase) to keep plants flowering until autumn.
• After the first frost blackens the foliage, lift tubers and store dry and frost-free over winter, or protect in the ground with a thick mulch in milder areas.

Top Tip:
White dahlias are the ultimate “mixers”—use them to soften bold colours in the border, or plant with deep purples and dark foliage for a really striking contrast.

Plant Details

Flowering Period:

July - October (until first frosts)

Height:
24–36" (60–90cm) (approx. depending on conditions)

Position:
Full sun

Tender Perennial:
Overwinter tubers frost-free in the UK