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Phlox

Perennial Phlox

Phlox paniculata

Also known as: Garden Phlox, Summer Phlox

  • Perennials
  • Zone 3a
  • Full Sun to Part Sun
  • Medium
  • 60–90 cm
  • 45–60 cm
  • 45–60 cm
  • Medium
  • Thriller

Bloom window: Mid to Late Summer

Perennial Phlox (garden phlox) produces fragrant summer flower clusters in pinks, purples, reds, and whites on upright stems. A classic border perennial for sunny Manitoba gardens with average moisture.

Soil
Well-drained, Loam
Native status
Introduced
Growth rate
Moderate
Flower colour
Pink, Purple, Red, White
Foliage colour
Green
Foliage habit
Deciduous
Landscape use
Border, Cut flower, Mass planting
Attracts
Bees, Butterflies, Hummingbirds

Care guides

Watering

Water Perennial Phlox deeply whenever the top 3–5 cm of soil dries during spring establishment and peak bloom. A thorough weekly soak usually outperforms light daily misting, especially on Manitoba clay that crusts in wind. Maintain even moisture through the bloom window, then ease back slightly as plants prepare for dormancy. Keep water off foliage late in the evening when possible to reduce foliar disease pressure.

Sunlight

Perennial Phlox (Phlox paniculata) should be placed in full sun or part sun. Aim for strong morning sun and lighter afternoon conditions—about 4–6 hours of direct light is usually ideal. In Steinbach heatwaves, unfiltered late-afternoon sun can pause flowering or crisp soft foliage, so a site with dappled afternoon relief often outperforms an all-day reflective south wall. Deep shade, however, stretches stems and cuts bloom count sharply. At a mature size around 60–90 cm, give neighbouring plants enough space so they do not shade out the crown as the season progresses.

Pruning

Deadhead spent blooms on Perennial Phlox through the season to tidy the clump and, for many varieties, encourage side shoots or a lighter rebloom. After hard frost, cut deciduous stems back to a few centimetres above the crown, or leave ornamental seed heads standing for winter structure and wildlife if the stems stay sturdy. In early spring, clear remaining straw-like foliage before new shoots emerge. Divide crowded clumps every few years in spring or early fall to renew vigour and flowering.