Phlox has two personalities. If you like a casual look, try
low-growing annual phlox, which produces an abundance of colorful blooms
on plants 6 to 20 inches high. For a formal, more stately bloomer, try
perennial summer phlox; varieties available include ones that tower to a
dramatic 5 feet, as well as newer ones like the one pictured at right,
which reaches only 1 to 2 feet.
In mildest-winter areas of Southern California and the desert,
plant annual phlox now to give it a head start in winter rains; wait
until spring elsewhere. Perennial phlox is most available in spring.
Colors for both include pink, lavender, salmon, purple, and white.
You can get annual phlox in some bicolors. Often perennial garden phlox
has a contrasting dot of color at the center of each floret.
Both types appreciate fast-draining soil with plenty of organic
matter, and abundant water. Feed regularly throughout the growing
season. Since flowers fade in intense sun, provide some afternoon shade
in hottest areas. With perennial phlox, you may need to apply fungicide late in the season for mildew. Where summers are hot and dry, mites may
need control–spray kelthane if infestation is severe. Annual phlox
In mild-winter areas, annual phlox out-performs the perennial
kinds. Plants look good massed in borders, window boxes, and flower
You can choose from a range of heights (6 to 20 inches) and
varieties with unusual star-shaped blooms, as well as ones with classic
smooth-edged flowers. These dwarf types grow 6 inches tall. The taller
strain, Finest, is not often sold as plants but is obtainable as seed.
To prolong bloom, keep spent flower picked. Summer phlox (P. paniculata)
Also called perennial garden phlox, it grows best where winters are
cold. It also grows successfully in milder areas that get some winter
chill. It languishes in coastal California, since winters are not cold
enough for sufficient chilling, and cool summers promote mildew.
Striking blooms appear on upright stalks throughout the summer. You
can now get these in more compact forms, such as the 2-foot-tall
‘Sandra’. Also available is the extra-dwarf ‘Pinafore
Pink’, which stays under a foot high.
Cut off faded flower heads to encourage lateral blooms. You will
probably want to weed out volunteer seedlings since they tend to revert
to the common magenta color. Stake to keep taller plants from toppling.
Plants will usually need dividing after three years.