Why Are My Kiwi Leaves Curling?

Aphids

Aphids are the most common cause of leaf curling on kiwi in UK gardens. Several aphid species colonise kiwi shoot tips in spring and summer, causing the young leaves at the growing points to curl and pucker tightly around the feeding colonies. The aphids are visible inside the curled leaves on close inspection. Kiwi vines are vigorous and a well-established plant tolerates moderate aphid infestation well; the damage is more significant on young, newly planted vines where the available leaf canopy is smaller.

What to do

• Inspect kiwi shoot tips in April and May. Natural predators (ladybirds, hoverfly larvae, parasitoid wasps) typically regulate aphid populations on established vines without intervention. For persistent or heavy infestations on young vines, apply insecticidal soap to the growing tips, covering the underside of curled leaves as well as the shoot surface.
• Avoid broad-spectrum insecticides that would kill the natural enemies. In a well-balanced garden with a diversity of plants and beneficial insect habitats, kiwi aphids are usually self-limiting by midsummer.

Drought

Kiwi vines have large leaves that lose substantial amounts of water through transpiration on hot days. Vines grown against warm, south-facing walls are particularly susceptible to drought stress, as the wall absorbs heat and dries the soil nearby rapidly. Drought-stressed kiwi leaves curl upward at the margins and the plant may wilt noticeably in the afternoon heat even when the soil is moderately moist. Newly planted kiwi vines in their first and second summers require regular watering until the root system is established.

What to do

• Water kiwi deeply and regularly during dry spells, particularly in the first few years after planting. Mulch generously around the base of the vine (keeping a gap around the stem) to retain soil moisture and reduce the need for frequent watering. Established kiwi vines on open soil generally manage without irrigation except in prolonged drought.

Iron deficiency chlorosis

Iron deficiency is common on kiwi grown on alkaline or chalk soils. The leaves develop a characteristic interveinal chlorosis: the leaf tissue between the veins turns yellow or pale green while the veins themselves remain dark green, giving the leaf a network pattern. Young leaves are typically more strongly affected than older ones. Severely deficient plants produce small, pale, curled leaves and grow poorly. Iron is present in most soils but becomes unavailable to plant roots when the soil pH is above about 6.5.

What to do

• Apply sequestered iron (chelated iron), available from garden centres, to the soil around the vine following the manufacturer's instructions. Chelated iron remains available to plant roots across a wider pH range than inorganic iron salts. A foliar spray of sequestered iron provides a faster but more temporary correction.
• For long-term management, lower the soil pH by incorporating sulphur or acidic organic matter (pine bark, composted bracken) into the soil around the vine over several years. Kiwi performs best at pH 6.0 to 6.5.

Late frost damage

Kiwi vines break dormancy relatively early in spring and the soft, emerging shoots are vulnerable to late frosts. Frost-damaged kiwi shoots blacken and collapse, and the leaves at the growing tips may curl, blacken, and die. The vine typically regenerates new shoots from dormant buds lower on the framework, but frost damage in May can remove all the flower buds and eliminate that year's crop.

What to do

• Protect emerging kiwi shoots from late frosts with horticultural fleece. In frost-prone areas, delay training the new shoots until the frost risk has passed, leaving them to grow loosely so they can be quickly protected or sacrificed without damaging the framework.

Frequently asked questions

Why are my kiwi leaves curling?

Kiwi (Actinidia deliciosa and Actinidia chinensis) leaves curl most commonly because of aphids on the growing tips, drought stress, or iron deficiency chlorosis. Aphids colonising the soft growing tips of kiwi vines in spring and summer cause the young leaves to curl and pucker around the feeding colonies; the leaves at the shoot tip are typically densely covered in aphids and heavily curled. Drought stress causes the large leaves of kiwi to curl upward and droop in hot conditions when the root system cannot supply water quickly enough; kiwi vines grown against warm walls are particularly susceptible. Iron deficiency occurs when kiwi is grown on alkaline soils where iron is unavailable, causing the leaves to yellow between the veins while the veins themselves remain green, and the young leaves may curl and remain small.

Can kiwi be grown in the UK?

Yes, kiwi (Actinidia deliciosa) can be grown in the UK as a vigorous ornamental and fruiting vine, though it requires a sheltered, south or west-facing wall in full sun to reliably produce fruit. The vines are hardy enough to survive UK winters but need protection from late spring frosts, which can damage the emerging soft growth. Most kiwis require a male and female plant to produce fruit, so growers need at least one of each; however, self-fertile varieties such as 'Jenny' produce fruit without a pollinator and are popular for UK garden growing. Actinidia chinensis (golden kiwi) and some varieties of Actinidia arguta (hardy kiwi, much smaller fruit) are also grown in the UK. Kiwi vines grow very vigorously (capable of 6 metres or more in a single season) and require regular pruning to maintain a manageable framework and encourage fruiting. Fruit set and ripening in the UK is variable and depends heavily on summer warmth and length; the south and south-east of England are most reliably productive.

How do I control aphids on kiwi?

Aphids on kiwi are usually controlled effectively by natural predators (ladybirds, hoverfly larvae, parasitoid wasps) without intervention, as kiwi vines are large and vigorous enough to tolerate moderate aphid pressure without significant harm. For persistent or severe infestations on young vines or on shoot tips where fruit is developing, insecticidal soap applied to the affected growing tips provides contact control. Avoid broad-spectrum insecticides that kill beneficial predators. In practice, the most important time to watch aphids on kiwi is on young, newly established vines in their first two or three years: established, mature vines with a large canopy are rarely significantly harmed by aphids.

Why are my kiwi leaves turning yellow?

Kiwi leaves turning yellow between the veins (with the veins remaining green) is almost always iron deficiency chlorosis, caused by growing the vine on alkaline or chalky soil where iron is locked up in insoluble forms the roots cannot absorb. Kiwi prefers slightly acidic to neutral soil (pH 6.0 to 6.5) and performs poorly on alkaline soils. Correct iron chlorosis by applying a sequestered iron (chelated iron) product to the soil or as a foliar spray; this provides iron in a form the plant can absorb regardless of soil pH. For a longer-term solution, apply sulphur to the soil around the vine to gradually lower the pH. Uniform yellowing of older leaves is typically nitrogen deficiency; apply a balanced fertiliser in spring. Yellow leaves with brown margins and general decline in a waterlogged position indicate root rot.