The earliest phlox to be
cultivated was P. paniculata, which was sent to
Europe from Virginia in the early 18th century. Selected forms were on
the market by the early 1800s in England and by the mid 1800s in
France. The earlier modern selections of P. paniculata
were made during the mid 1900s in England by Symons-Jeune (reviewed by
Symons-Jeune 1953) and Alan Bloom (reviewed by Bloom 1991) and in
Germany by Georg Arends. Present day P. paniculata
breeding takes place for the most part in The Netherlands and the
Symons-Jeune and Bloom
selected mostly for flower size and color and for vigor. Although
Symons-Jeune seems to have had little understanding of the basis of
inheritance (cf. Symons-Jeune 1953, p. 81) he was a skilled breeder,
and many of his selections are still in the trade. Many of Bloom’s
selections, too, have become standard varieties. Arends was basically a
hybridizer and experimented with crossing P. paniculata
with other species. Some of his P. paniculata × P.
divaricata hybrids are still available.
These breeders explored the range of flower colors
pretty thoroughly, and present day breeding focuses on other traits.
The Dutch have been concerned for the most part with growth habit,
although there has been interest also in novelty floral mutations.
Breeding has involved reduction in height to 50-60cm combined with
sturdy stems and large flower heads. This trend is similar to that for
many other perennials in The Netherlands, where there is an emphasis on
pot presentation and shipping efficiency. There have been some very
handsome new plants of traditional height, though, most notably
selections like ‘Valentina.’ In the United States selection has
emphasized resistance to powdery mildew. Some apparently resistant
varieties are much closer to wild types in flower color and growth
habit than are those bred in Europe.
Other tall and
mid size species
also reached England from Virginia by the first half of the 18th
century. Symons-Jeune (1953) lists 10 named selections of P.
divaricata available, but in the 2008 RHS plantfinder these
have been replaced by new forms, almost all of which are US selections
from wild populations. Hybrids of P. divaricata × P.
paniculata (P. ×arendsii)
were offered for sale by Arends nursery by 1912. New cultivars of P. ×arendsii continue to come onto the market. It is
not clear if these are F1 hybrids or derived from seed made by P. ×arendsii parents.
Other members of the P.
divaricata group have been grown in gardens since the 1800s,
but named cultivars seem to be all selections from the wild. A few
hybrids, such as P. pilosa × P.
divaricata and P. amoena × P.
divaricata are grown. These are selections from the wild or
garden hybrids, and breeding does not seem to have been done past the
The P. glaberrima group made
its way to Europe by the mid 1700s, too. P. maculata
was used by Arends as a hybridization parent with other phlox, although
the results of his crosses do not seem to have survived. Selections
have been made of P. maculata, most notably by Alan
Bloom, and at the present time about a half-dozen cultivars of this
species are available. P. carolina and P. ovata reached England by the 1700s and P.
pulchra by the 1950s. They have been
grown as garden plants, but nothing seems to have been done to develop
new cultivars of these in Europe. In North America this group has been
almost ignored by mainstream gardeners except for a few cultivars of P.
maculata. The species are grown mostly by native plant
enthusiasts, although a couple of recent cultivars, P. glaberrima ssp. triflora ‘Morris
Berd’ and P. carolina ‘Minnie Pearl’ are
increasingly popular. True P. glaberrima and P.
do not seem to be in garden use. This group has
had a checkered taxonomic past, and the names of the species and
cultivars offered by nurseries are very confused. The British have
tended to continue to use obsolete species names, and the errors
and inconsistencies of authors like Symons-Jeune (1953) have not
Named selections, mostly of wild finds, have been
introduced of P. stolonifera and P.
adsurgens. A few hybrids of P.
stolonifera × P. subulata and P.
adsurgens × P. nivalis have been made
and introduced but are not mainstream garden plants.
Phlox subulata reached Europe
almost as early as P. paniculata. Many cultivars
have been selected there and in North America. P. bifida
and P. nivalis came into cultivation by the early
1800s, and a significant proportion of moss phlox available are hybrids
of these species with P. subulata. Some of the
western moss phlox are growable by alpine gardeners in Europe. Hybrids
have been made by British, German, and Czech growers of western species
with (apparently) P. subulata. These small and
very choice cultivars often do well in the eastern US, but are too
small to be grown by other than rock gardeners.