Phlox drummondii Seeds | Annual Phlox
LATIN NAME: Phlox drummondii
COMMON NAME: Annual Phlox
Plant Profile
Annual phlox is a low, bushy, branching annual from the sandy post-oak woods of Texas, growing fifteen to forty centimetres tall and about as wide. The leaves are narrow and sticky, and the stems are covered with fine hairs.
From June until the first frost it carries clusters of flat, five-petalled flowers two centimetres across, in white, cream, pink, salmon, scarlet and purple, often with a contrasting eye, and the scent is light and sweet in the evening. It is one of the most colourful of all annuals, and a bed of it in full flower looks like a spilled box of confetti. Twinkle and Beauty are long-standing seed strains, both raised in the nineteenth century.
Science & Biotechnology
The species was named for Thomas Drummond, the Scottish botanist and collector who found it in 1835 near the Brazos River in Texas and sent seed to Britain, where it flowered within two years. It is one of about sixty species of Phlox, all but one of them North American, and it sits in Polemoniaceae, a family that also includes the Jacob’s ladder and the gilia.
The genus is unusual in having a style that is three-lobed, and the flower shape is adapted to pollination by butterflies and moths, with a long tube that holds the nectar out of reach of short-tongued insects. The sticky hairs on the stems are a defence against small insects that would otherwise climb up and rob the nectar. The species is a diploid with 14 chromosomes, which is why it breeds true so quickly in cultivation.
Uses & Benefits
Annual phlox is used for bedding, for edging, for containers and for a cut flower, and it is one of the few annuals that will flower in light shade as well as in sun. It is also useful for filling gaps in a border in late spring, since it flowers within ten weeks of sowing.
The flowers are strongly scented in the evening, which makes them a good choice for a seat or a path, and they attract hawk moths. Dwarf strains suit the front of a border and window boxes, while the taller ones can be cut. The plant is not edible, and although it has a place in the folk medicine of its native Texas, it is grown in gardens purely for colour. It resents being transplanted, so it is best sown where it is to flower.
Growing from Seed
Sow in early spring at 15-18 °C on the surface of a free-draining compost, press the seed in and cover with a thin layer of vermiculite, since light improves germination. The seed is slow, taking three to four weeks, and it germinates unevenly.
Prick the seedlings out as soon as they can be handled, because they resent root disturbance later, and grow them on cool and bright. Harden them off gradually and plant out after the last frost, 20 centimetres apart, in full sun and in soil that drains. Pinch the tips once to make the plants bushy. Water at the base rather than overhead, since the foliage is prone to mildew, and deadhead regularly to keep the flowers coming until the frost.
Our Take
The brightest annual for a dry, sunny bed, flowering within ten weeks of sowing and scented in the evening. Sow it where it is to grow.
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