When to plant
Plant bare-root phlox in early to mid-spring once the soil has warmed, or in early autumn so plants can establish before winter. Avoid planting in very wet or frozen soil. Container-grown phlox can be planted any time during the growing season.
Where to plant
Choose a sunny or lightly shaded position with 4–6 hours of direct sunlight per day. Phlox thrive in borders, cottage gardens and pollinator plantings. Ensure good air circulation around plants to reduce the risk of mildew.
Preparing the soil
Loosen the soil to 20–25 cm deep and enrich with compost or well-rotted manure. Phlox prefer fertile, moisture-retentive but well-drained soil. Improve very sandy soils with compost, and lighten clay soils with grit and organic matter.
Preparing the plants
For bare-root phlox, soak the roots in lukewarm water for 15–20 minutes before planting to rehydrate them. Trim only damaged roots if necessary. For potted plants, water well before planting and gently loosen circling roots.
Planting the plants
Dig a hole large enough to spread the roots comfortably. Plant at the same depth as the crown sits naturally, keeping the growing points just above soil level. Space plants 40–60 cm apart for good airflow. Firm the soil and water thoroughly.
After planting
Keep the soil evenly moist while plants establish. Mulch lightly around the base (not directly against the stems) to retain moisture and keep weeds down.
During growth
Water regularly during dry spells—phlox do not like to dry out. Apply a balanced slow-release fertiliser in spring. Deadhead spent flowers to encourage extended blooming. Watch for mildew and ensure plants have enough spacing and airflow.
After flowering / end of season
Cut back stems to ground level in late autumn once foliage has died back naturally. In mild climates, tidy only after the plant fully senesces. Divide clumps every 3–4 years in early spring or autumn to maintain vigour.
Extra tips
Phlox pair beautifully with echinacea, delphiniums, salvias and ornamental grasses. Water at the base to avoid wetting foliage. Ideal for gardeners seeking long-lasting summer colour with strong pollinator appeal.
