PL. —Hosta plantaginea var. grandifloraBotanical illustration — drop image
Hosta plantaginea var. grandiflora

August Lily

SpringSummerFall
3a9aHardiness zone
Peak bloom windowZone 6b · frost-offset weeks
Winter
Not in bloom
Spring
In bloom
Summer
Peak bloom
Fall
Not in bloom
Peak bloom
In bloom
Background

August Lily is a large, clump-forming hosta native to eastern China and one of the very few members of the genus grown as much for its flowers as its foliage. In late summer, tall scapes carry pure-white, trumpet-shaped flowers that are heavily fragrant, particularly in the evening — a trait almost unique in the genus. The leaves are broad, glossy, and bright green, warmer in tone than the blue-green typical of most hostas.

Unlike most hostas, H. plantaginea var. grandiflora requires adequate light to flower reliably; deep shade reduces or eliminates the bloom. It does best in moist, humus-rich, well-drained soil with consistent moisture. A thick layer of organic mulch over the root zone conserves moisture and moderates soil temperature. Plants emerge late in spring, later than almost any other hosta, so avoid disturbing the crown during early-season soil work. In zones 3–5, a light winter mulch prevents freeze-thaw heaving. Slugs are the most persistent pest and target the soft emerging shoots with particular intensity.

In traditional Chinese medicine, the flowers (known as yùzān huā) are used for throat inflammation, carbuncles, and ulcers. The roots, applied externally for carbuncles, contain saponins and are toxic if ingested. The fragrant, evening-opening flowers attract hawk moths and other long-tongued pollinators, giving this plant genuine ecological value in a shade garden context.

Care guide
SunPart shade to full shade
WaterRegular
SoilMoist, well-drained, rich
Spacing24–36 in
Height18–36 in
Zone3a – 9a
Frost hardy
Seasonal tasks
spring
watchAs shoots emerge, inspect for slug and snail damage; apply iron phosphate bait or set traps around the crown.
sowDivide crowded clumps by lifting the root mass and cutting into sections with a sharp spade; replant divisions at the same depth they were growing.
summer
watchMonitor soil moisture through dry spells and water at the base; inconsistent moisture causes marginal leaf scorch on the large leaves.
watchInspect foliage for vein-bounded yellow or tan streaking indicating foliar nematode infection; remove and destroy affected leaves immediately and cease all overhead watering.
cutRemove spent flower scapes at ground level once the white flowers have finished, typically by early September.
fall
cutCut all foliage to ground level after the first hard frost blackens the leaves.
sowApply 2–3 in of shredded bark or leaf mulch over the crown to buffer against freeze-thaw cycles, especially in zones 3–5.
Common problems

Crown Rot

Symptoms

Lower leaves yellow and wilt; the base of the rosette turns brown and soft, sometimes with white fungal threads at the soil line. Plants collapse in wet conditions.

Treatment

Remove and destroy affected plants. Improve drainage and avoid overhead watering. Do not mulch directly against the crown. Space plants for airflow and avoid replanting in the same wet spot.

Botrytis (grey mould)

Symptoms

Grey fuzzy mould on petals and stems, worst in cool wet conditions.

Treatment

Remove affected parts immediately. Improve air circulation. Avoid overhead watering. Apply copper fungicide if severe.

Fungal leaf spot

Symptoms

Brown or purplish spots on the leaves, often ringed with a yellow halo, that spread and merge in warm, humid, or wet weather; heavily spotted leaves yellow and drop early.

Treatment

Pick off spotted leaves and clear fallen debris to remove overwintering spores. Improve air circulation by thinning, and water at the base so foliage dries quickly. If it persists, apply a copper- or sulfur-based fungicide at the first sign.

Root rot

Symptoms

Plants wilt, yellow, and stunt even in moist soil; lower stems and roots turn brown, soft, and mushy and the plant may collapse. Most common in heavy, wet, or poorly drained ground.

Treatment

Improve drainage and stop overwatering, and never plant too deep. Lift and destroy badly affected plants along with the soil around the roots. Grow in raised or free-draining beds to prevent it returning.

Hosta Foliar Nematode

Symptoms

Yellow to tan or brown streaks develop between leaf veins, sharply bounded by the vein structure, producing a distinctly striped or angular pattern. Affected tissue turns brown and necrotic as the season progresses; severely infected leaves curl and collapse.

Treatment

Remove and destroy all affected leaves as soon as symptoms appear. Avoid overhead watering and any activity that spreads water across foliage, as nematodes travel in moisture films. Do not divide or transplant infected clumps. No reliable chemical control exists; prompt removal of infected foliage combined with strict avoidance of leaf wetness is the primary management approach.