Tufted phlox
Phlox douglasii · Polemoniaceae
📷 Hectonichus · CC BY-SA 3.0
The gardener's calendar
Ideal time to plant tufted phlox: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Family
- Polemoniaceae
- Type
- Herbaceous perennial
- Foliage
- Semi-evergreen to deciduous depending on climate
- Flowering
- May to June
- Mature size
- Approximately 25 cm in height
- Exposure
- Full sun
- Hardiness
- Very hardy (down to -20 °C)
- Origin
- Western United States (Rocky Mountains)
✓ Taxonomy verifiedSource: AI estimate · hardiness: reliability high.
Expert tips
The key tip
Pinch back after flowering to encourage basal branching. Very well-draining soil is essential; heavy soil will weaken it.
The common mistake
Don't plant it in heavy or clay soil, even "improved" clay—it'll end up waterlogged anyway and really only thrives in light/sandy/rocky soil.
The pro's trick
Sow in autumn on a prepared slope (rock garden): it'll germinate without watering in spring.
Care
Exposure
Douglas phlox demands full sun to express all its floral splendor. Install it in a location receiving at least 6 hours of direct sunlight daily. A sunny exposure promotes dense flowering and more vibrant colors.
Watering
Keep the soil moderately moist during growth and flowering, without ever allowing it to become waterlogged. Reduce watering in winter, especially if the plant is exposed to regular rainfall. In pots, check substrate moisture before watering again.
Soil
Douglas phlox prefers well-drained soil, preferably light and slightly acidic to neutral. Avoid heavy, clayey soils that promote root suffocation. Enrich the soil with compost or potting soil when planting.
Pruning and cleanup
After flowering, deadhead spent flowers to stimulate a second flowering wave at the end of the season. In late autumn or early winter, cut the vegetation down to ground level. This pruning promotes vigorous regrowth in spring.
Fertilizer
A spring application of balanced fertilizer is generally sufficient to support flowering. In poor soil, supplement with moderate fertilizer in May-June. Avoid excess nitrogen, which would reduce flowering in favor of foliage.
Pests and diseases
Douglas phlox is generally robust. Remain vigilant against powdery mildew in cases of stagnant humidity and poor air circulation. Water at the base (not on the foliage) to limit these risks. Regularly aerate the clump.
Did you know?
Douglas phlox is named after botanist David Douglas, a Scottish explorer of the nineteenth century who collected thousands of plants in the American West. This small hardy perennial, with its delicate clustered flowers, was used by indigenous peoples to embellish their traditional gardens. Its scientific name douglasii pays homage to his legendary botanical explorations in North America.
Where to buy it
Plant in spring or early autumn, avoiding spells of intense heat. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, April, May, September.
Add this plant to my garden →Plants from the same family
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- Jacob's ladderPolemonium reptans
Tips generated and checked by Viridia — adapt them to your local climate.