Common Name: garden phlox
Type: Herbaceous perennial
Family: Polemoniaceae
Zone: 4 to 8
Height: 2.00 to 2.50 feet
Spread: 1.50 to 2.00 feet
Bloom Time: July to September
Bloom Description: Lilac purple
Sun: Full sun to part shade
Water: Medium
Maintenance: Medium
Flower: Showy, Fragrant
Attracts: Birds, Hummingbirds, Butterflies
Tolerate: Deer, Clay Soil, Black Walnut
Culture
Grow in moderately fertile, medium moisture, well-drained soil in full sun to part shade. Best in full sun. Prefers rich, moist, organic soils. Needs good air circulation (space well and thin out stems as needed) to help combat potential powdery mildew problems. Intolerant of drought and needs to be watered in dry spells. Avoid overhead watering however. Appreciates a summer mulch which helps keep the root zone cool. Stiff upright plant stems do not need staking.
Noteworthy Characteristics
Arendsii hybrids are crosses between Phlox paniculata and Phlox divaricata, and are noted for having the attractive flowers of the former combined with the compact form of the latter. Each individual floret has a long corolla tube and five flat petal-like lobes. Butterflies love the flowers. This is an upright, conical perennial that typically grows in a clump to 30" tall on stiff stems clad with narrow, opposite, pointed, elliptic, deep green leaves (to 4” long).
The genus name is derived from the Greek word phlox meaning flame in reference to the intense flower colors of some varieties.
‘Hesperis’ is a vigorous arendsii hybrid phlox cultivar that produces fragrant, tubular, lilac-purple florets densely packed in terminal clusters over a long July to October bloom period.
Problems
Phlox is not always an easy plant to grow well. Powdery mildew and root rot can be serious problems. Spider mites and plant bugs can also be a problem, particularly in hot, dry conditions.