© RHS/Tim Sandall


Annual phlox

Flowering through summer, half-hardy annual phlox, Phlox drummondii cultivars and seed-raised mixes, can add colour to borders and large containers. Alternatively, use them to fill in gaps at the front of your borders.


These compact plants of 10-45cm (4-18in) high bear clusters of flowers in white, pink, dusky red, lavender, purple and blue. The blooms are held above lance-shaped, pale-green foliage.


Very poor, dry soil stunts growth. Consider improving with well-rotted garden compost and manure and water well in dry spell to get over this hurdle.

Did you know?

Like perennial-border phlox, annual phlox are useful as cut flowers. Remove stems that have finished flowering to encourage plants to go on producing more.

Growing guide

Annual phlox we recommend

Useful advice

Hardening off tender plants

Hardening off tender plants

Get involved

The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.