Mt Cuba Center
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Carex barrattii
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Mt. Cuba Center evaluates native plants and related cultivars for horticultural and ecological value.

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Mt Cuba Center
Back to trial Phlox for Sun

Trial Garden

Phlox glaberrima ssp. triflora

5 Photos


Phlox glaberrima ssp. triflora is quite different from Phlox glaberrima. In fact, some horticulturists advocate for elevating this subspecies to its own species. The distinguishing characteristics of an earlier bloom time and persistent overwintering basal foliage are indeed unique. Phlox glaberrima ‘Morris Berd’ also belongs to this subspecies, although the name is usually written without the subspecies. Based on the performance in our trial, we would recommend using ‘Morris Berd’ over Phlox glaberrima ssp. triflora as it is more vigorous and robust.


  • Rating
  • Common Name
    smooth phlox  
  • Bloom Period
    late May—early June 
  • Peak Bloom
    early June 
  • Size
    24” x 36” 
  • Fragrance
    none observed 
  • Powdery Mildew Resistance