Woodland Phlox ‘Blue Moon’ (Phlox divaricata ‘Blue Moon’)

Woodland Phlox 'Blue Moon' botanical diagram

About Woodland Phlox 'Blue Moon'

Woodland Phlox 'Blue Moon' (Phlox divaricata ‘Blue Moon’) is grown for garden performance matched to its site needs. Expect partial sun, typically 0.3–0.61 m tall, moderate water once established.

Sun Partial
Water Moderate
Height 1–2 ft (30–60 cm)
Spread 2–3 ft (60–90 cm)
Bloom Apr–May [1]
Habit Herbaceous Perennial
Origin North America, Manizales, Alabama, Arkansas, Connecticut, Delaware, District of Columbia, Florida, United States [2]
Season Spring
Hardiness Zones 4–8

Can Blue Moon take your winter? Type your ZIP below and compare it with Zones 4–8.

2023 USDA ZIP listings (PRISM / USDA-ARS). Find Your USDA Hardiness Zone · Official USDA map.

Is Woodland Phlox 'Blue Moon' Right for Your Garden?

Best for

  • Mixed borders and general garden use
  • Wildlife-friendly gardens — known to attract butterflies

Trade-off to know

Woodland Phlox 'Blue Moon' suits most garden soils when drainage is adequate. The main limitation is site scale — match plant size to available space.

Growing Conditions for Woodland Phlox 'Blue Moon'

Site checklist

  • Sun: partial sun
  • Soil drainage: Moist but Well Drained
  • Water: Moderate
  • Hardiness zones: 4, 5, 6, 7, 8

Adjustments

  • Wrong light level is the most common cause of weak performance
  • Fix drainage before treating leaf symptoms

Shared growing steps for this plant’s group: How to Grow Phlox. Notes below stay specific to this plant.

How to Care for Woodland Phlox 'Blue Moon'

Establishment

  1. Plant Woodland Phlox 'Blue Moon' in a site matching its sun and drainage needs
  2. Water regularly until roots settle, then match watering to the plant’s need

Ongoing care

  • Mulch to buffer moisture swings
  • Remove dead or damaged growth in season
  • Avoid constant wet foliage where disease pressure is high

Diagnosing Problems with Woodland Phlox 'Blue Moon'

SymptomLikely causeConfirming signAction
Leaves yellowing unevenly across the plant Uneven watering or compacted soil Yellowing worse on one side; soil hard or crusted at surface Water Woodland Phlox 'Blue Moon' deeply and evenly. Loosen surface compaction with a fork; avoid disturbing main roots.
Sudden wilting on one branch while rest of plant looks healthy Root rot from poor drainage in one spot Affected branch has dark, mushy roots when gently uncovered Cut back affected branch to healthy wood. Improve drainage in that area before the next growing season.

Leaves yellowing unevenly across the plant

Likely cause
Uneven watering or compacted soil
Confirming sign
Yellowing worse on one side; soil hard or crusted at surface
Action
Water Woodland Phlox 'Blue Moon' deeply and evenly. Loosen surface compaction with a fork; avoid disturbing main roots.

Sudden wilting on one branch while rest of plant looks healthy

Likely cause
Root rot from poor drainage in one spot
Confirming sign
Affected branch has dark, mushy roots when gently uncovered
Action
Cut back affected branch to healthy wood. Improve drainage in that area before the next growing season.

Woodland Phlox 'Blue Moon' FAQ

  1. Is Woodland Phlox 'Blue Moon' easy to grow?

    Woodland Phlox 'Blue Moon' is manageable for most gardeners if sited correctly from the outset. The most common mistakes are poor drainage and incorrect sun placement.

  2. How big does Woodland Phlox 'Blue Moon' get?

    Woodland Phlox 'Blue Moon' typically reaches 0.3–0.61 m. Final size depends on soil quality and available root space. Allow adequate spacing at planting — most plants reach their full spread within 5–10 years.

  3. How much sun does Woodland Phlox 'Blue Moon' need?

    Woodland Phlox 'Blue Moon' grows best in partial sun. Planting in the wrong light level is the single most common cause of poor performance. Check the aspect of your site before choosing a position.

  4. Does Woodland Phlox 'Blue Moon' attract wildlife?

    Woodland Phlox 'Blue Moon' is known to attract butterflies, hummingbirds. For maximum benefit, avoid deadheading all flowers — seed heads and spent blooms are often as valuable to wildlife as the flowers themselves.

What Woodland Phlox 'Blue Moon' Symbolises

  • harmony
  • sweet
  • unifying
  • bright

References

  1. [1] GBIF occurrence phenology — Bloom months inferred from StillImage observation seasonality (temperate Northern Hemisphere filter). Not an official cultivar calendar. - https://www.gbif.org/species/2927730
  2. [2] GBIF species distributions — Native range summarised from GBIF distribution records; locality noise filtered to country and macro-region terms. - https://www.gbif.org/species/2927730

Taxonomic identifiers

  • https://www.gbif.org/species/2927730 (GBIF 2927730)
  • https://www.wikidata.org/wiki/Q5222804 (Wikidata Q5222804)
  • https://powo.science.kew.org/taxon/tro-25800377 (POWO tro-25800377)
  • https://www.ipni.org/n/193437-2 (IPNI 193437-2)

Plant details on Bosquelle are curated from published references and garden practice. Height, bloom time, hardiness, and look still shift with climate, soil, and care — use this profile as a reliable starting point, then check what local growers see in your area.