Why Are My Disporum Leaves Curling?

Slug damage

Slugs are the most common cause of disporum leaf curl in UK gardens. The soft, lance-shaped leaves are attractive to slugs, which feed on the emerging shoots in spring and on the expanded leaves through the growing season. Slug feeding causes the leaf margins to curl around the damage, with ragged holes and silvery slime trails as additional signs. In the moist, shaded conditions that disporum prefers, slugs are abundant year-round, and established disporum colonies in slug-prone gardens can suffer repeated annual damage that gradually weakens the plants over time.

What to do

• Apply biological nematode slug control (Phasmarhabditis hermaphrodita) around disporum in spring when soil temperatures are above 5 degrees Celsius. Time the application to protect the most vulnerable emerging shoots.
• Apply a ring of sharp grit or copper tape around the emerging shoots. While not entirely effective against all slug species, this reduces damage from the less aggressive types.
• Hand-collect slugs from around disporum in the evening with a torch, particularly in warm, wet spring weather. Systematic checking in the evening is the most reliable low-intervention control method.
• Iron-phosphate slug pellets are safe to use around disporum and do not harm hedgehogs, birds, or other garden wildlife.

Drought stress

Disporum is a woodland-floor plant and requires consistently moist, cool, humus-rich soil. In dry, exposed positions or during unusually dry UK summers, the lance-shaped leaves curl inward along their length to reduce moisture loss. The plant loses its characteristic fresh green lustre, the leaves may develop brown, papery tips, and the normally upright-to-arching posture of the stems becomes limp. Drought stress is most common in disporum planted in positions that receive more sun than the plant needs, or in shallow, sandy, fast-draining soil.

What to do

• Water disporum during dry periods through the growing season. The rhizomes have moderate reserves but cannot sustain growth through prolonged dry spells.
• Apply a generous mulch of leafmould or garden compost around disporum each spring. This retains soil moisture, keeps the root zone cool, and progressively enriches the soil.
• Ensure disporum is planted in a shaded position: the leaf canopy of deciduous trees and shrubs significantly reduces soil drying and creates the cool, moist microclimate the plant requires.

Late frost damage

The emerging shoots and fresh leaves of disporum are frost-sensitive. A late spring frost in April or May can cause the new growth to curl, brown, and collapse. This is particularly a problem for some of the Asian disporum species, which can be slightly less hardy than the native North American species. However, established plants with healthy rhizomes typically regenerate new growth after mild frost damage within two to three weeks of the frost event.

What to do

• Cover emerging disporum growth with horticultural fleece when frost is forecast in spring. The low-growing habit of most disporum makes fleece protection straightforward.
• Plant disporum under deciduous trees or shrubs that provide natural frost protection from radiation frost, replicating the overhead canopy of its natural woodland habitat.
• Apply a generous winter mulch of leafmould or bark, 8 to 10 cm deep, over the planting area in late autumn to insulate the rhizomes from deep frosts.

Too much sun

Disporum is a shade plant and performs poorly in full sun. In sunny positions, the lance-shaped leaves curl inward and develop bleached or scorched patches on the upper surface. The normally rich green foliage becomes yellowish and the plant fails to produce the strong, vigorous stems typical of well-sited specimens. Full sun also accelerates soil drying, compounding the drought stress effect.

What to do

• Relocate disporum to a dappled-shade or full-shade position under deciduous trees or on the north or east-facing side of walls and structures. East-facing positions that receive morning sun but shade from midday onwards are acceptable in moist soil.
• If the plant is in a sunny position that cannot be changed, plant taller shrubs or perennials to provide shade from the south and west, and maintain generous moisture and mulch.

Poor soil

Disporum requires reasonably rich, humus-rich, moisture-retentive soil to produce strong stems and healthy foliage. In poor, thin, or very sandy soil, the plants produce smaller leaves that may curl at the margins as individual rhizomes are resource-limited. Slow growth, weak stems, and pale foliage often accompany the leaf curling in genuinely poor soil conditions.

What to do

• Incorporate generous quantities of leafmould or well-rotted garden compost into the planting area before establishing disporum. Good initial soil preparation is the most effective long-term investment.
• Top-dress around established disporum each spring with a layer of leafmould or garden compost to continue improving soil structure and organic matter content over time.
• Feed established disporum with a balanced granular fertiliser in early spring if growth is notably weak and the soil is thin or low in fertility.

Frequently asked questions

Why are my disporum leaves curling?

Disporum leaves curl most often from slug damage or drought stress. Slugs attack the emerging shoots in spring and cause the fresh leaves to curl and develop ragged holes as the feeding damage causes the tissue to collapse. Drought stress in dry, sunny positions causes the lance-shaped leaves to curl inward to reduce moisture loss, as disporum naturally grows in cool, moist, humus-rich woodland conditions.

What is the difference between disporum and polygonatum?

Disporum and polygonatum are both woodland-floor perennials with similar arching stems and lance-shaped leaves, and are often confused. The main differences are in the flowers and berries: disporum flowers are typically larger, more flared, and often pendent at the stem tips rather than hanging along the stem as in polygonatum; and disporum berries tend to be larger and more conspicuous. Some disporum species, particularly the Asian species such as Disporum cantoniense, grow taller and have more dramatically coloured flowers than most polygonatum.

What conditions does disporum need?

Disporum thrives in cool, moist, humus-rich, well-drained soil in dappled shade or deep shade, replicating its native woodland-floor habitat. It benefits from soil enriched with leafmould and garden compost and requires consistent moisture through the growing season. It is generally hardy in UK conditions, though some of the more exotic Asian species may need some frost protection in colder gardens. Plant disporum in a sheltered, shaded position to protect the emerging growth from late spring frosts.

When does disporum flower?

Disporum flowers in late spring and early summer, from May to June, producing pendent, tubular or bell-shaped flowers at the tips of the arching stems. The flowers are followed by ornamental berries in late summer and autumn that range from white to yellow, orange, red, or black depending on the species. The berries are often the most striking feature of the plant and persist well into autumn after the leaves die back.