Colour me happy! Fragrant phloxes help brighten up those tricky gaps between seasons

A well-planted garden plays like a classical symphony. After a quiet beginning, spring builds up a steady crescendo. This peaks in June with lupins, huge poppies and a riot of roses. Then there’s a pause. July is a quieter, greener month, full of promises yet to be delivered.

That is why border phloxes are such valuable summer perennials. They can colour that gap, flowering when rudbeckias, heleniums and other short-day plants are barely into bud.

Colourful, fragrant and with sturdy stems, phloxes look beautiful and the best could carry flowers in September.

Among tall phloxes, colours run from pink or violet-blue through mauves and blushes to shocking pink. Many are bicoloured, often with dark centres and lighter petals. Their honeylike fragrance can fill the air.

Border phloxes grow best in fertile, free-draining soil, especially if it’s rich in organic matter and stays moist. They’re easy to grow and blend happily in a mixed planting scheme.

Almost all phloxes are native to North America. Many are ground-covering, lovely for rock gardens. Tall border phlox varieties were developed from two wild species: Phlox paniculata and the similar P. maculata.

BORDER BEAUTIES 

Like most hardy perennials, phloxes are easy to grow. The most rugged, white-flowered Mount Fuji, aka Fujiyama, is closest to the wild P. paniculata. It’s a rapid clump-former. Its flowers are smaller than fancy varieties, but that makes them durable. The panicles, or flower clusters, are generous, too.

One of the most intensely coloured is Starfire: a red-pink. If that’s too dazzling, Bright

Eyes may be better. It has pink flowers, each with a darker eye.

Among violet and mauve phloxes, I planted Blue Paradise whose panicles are deep indigo. I also plan to grow the violetblue Franz Schubert.

There are dozens of varieties but make room for P. maculata, or Meadow Phlox. That grows with more slender stems and narrower leaves. Individual flowers are slightly smaller but plentiful, carried in clusters.

Wild American P. maculata has pink flowers. Among garden varieties, Alpha has mauve-pink flowers and Omega’s are white with lilac. All are fragrant. 

PERENNIAL PICKS 

Perennial phloxes are model border plants. They team well with most summer perennials and can flower for long periods.

Although management is easy, they have one serious pest: phlox stem eelworm. These are nematodes that cause stunted or swollen shoots and abnormally shaped leaves. Unlike other eelworms, this one does not affect the roots. That means you can avoid the pest by growing plants from root cuttings.

Take those between October and Christmas. Dig up mature plants and wash the soil from the roots. Snip a few of the thickest roots, cutting each into 4 to 6 cm lengths. You’ll need to remember which way up those are, so cut each lower end obliquely and the top vertically.

Fill a pot with growing medium.

Insert cuttings with the tips just below the soil surface. Leave the pots in a cold-frame or a sheltered corner. Pot up the plants when large enough, next spring. Growing from root cuttings may seem hard, but they have a high success rate.