Why Are My Chives Leaves Curling?

Onion thrips

Onion thrips (Thrips tabaci) are tiny, slender insects that rasp the outer surface of chive leaves, feeding on the cell contents and leaving characteristic silver-grey, mottled streaking on the leaf surface. In heavy infestations, the leaves curl, distort, and develop a bleached, papery appearance. Thrips are most active in hot, dry, sunny conditions from June to September and are significantly worse on plants growing in dry soils.

What to do

• Water chives consistently during dry spells: thrips are much less damaging on well-watered plants in moist soil. This is the most effective cultural control.
• Cut badly affected chive clumps to within 5 centimetres of the ground: the plant re-shoots with clean, fresh leaves within 2 to 3 weeks. Removing the damaged foliage also removes the thrips living within it.
• Blue sticky traps placed near chive clumps catch adult thrips and help reduce populations: thrips are attracted to the blue colour.

Allium leaf miner

Allium leaf miner (Phytomyza gymnostoma) is a fly whose larvae mine inside the hollow leaves of chives, leeks, onions, and other alliums. On chives, the larvae bore through the leaf base, causing the tips to turn white, wither, and collapse. Small white pupae are sometimes visible inside the base of affected leaves. The fly has two generations per year in the UK (March to April and October to November) and has spread significantly across England since its first UK record in 2002.

What to do

• Cover chive clumps with fine insect mesh during the two main flight periods (March to April and October to November) to prevent the adult fly from laying eggs on the leaves.
• Cut affected chive clumps to the ground and destroy the cut material, killing any pupae present. The plant will re-shoot within 2 to 3 weeks.

Downy mildew

Downy mildew on chives (Peronospora destructor, the same species as onion downy mildew) produces pale grey or violet patches on the leaves that turn yellow and wither as the infection progresses. The affected leaves may curl slightly and collapse. Downy mildew is most common in cool, humid conditions in spring and autumn and on congested, poorly ventilated clumps.

What to do

• Cut affected clumps to the ground and remove the cut material. Improve airflow by dividing and thinning congested clumps.
• Avoid overhead watering and water at the base of the clump to keep foliage dry.

Drought

Drought causes chive leaves to turn yellow and collapse at the tips, then progressively from the tips downward. In prolonged drought in summer, chives die back entirely to their bulb clumps below ground: this is a natural drought-avoidance response and not a sign that the plant is dead. The clumps re-shoot when cooler, wetter conditions return in autumn.

What to do

• Water chives during dry spells, particularly those growing in pots and containers, which dry out faster than garden soil. Allow natural summer die-back in very dry conditions rather than over-watering to the point of waterlogging, which causes root rot.

Congested clumps

Chive clumps that have not been divided for several years become increasingly congested at the centre, with the bulbs competing for space, nutrients, and water. Congested clumps produce thinner, more yellow leaves and are more susceptible to pests and diseases. The outer edges of the clump remain productive while the centre becomes hollow and unproductive.

What to do

• Divide chive clumps every 2 to 3 years in spring or autumn: lift the entire clump, split it into sections of 6 to 10 bulbs each, and replant in fresh, composted soil. This renews the vigour of the plant and produces noticeably larger, more productive growth.

Frequently asked questions

Why are my chives leaves curling and yellowing?

Chives leaves curl and yellow most often from onion thrips, downy mildew, or allium leaf miner. Onion thrips (Thrips tabaci) rasp the surface of chive leaves, causing silver-grey, mottled streaking that is associated with leaf distortion and curling. Downy mildew (Peronospora destructor) produces pale grey or violet patches on the leaves that cause yellowing and withering. Allium leaf miner (Phytomyza gymnostoma) is an increasingly common pest of all allium family plants in the UK; the larvae mine inside the hollow chive leaves, causing the tips to turn white, wither, and collapse. Chives are generally robust plants that bounce back quickly from most problems if the damaged leaves are cut to the ground and allowed to regrow.

Why are my chives turning yellow?

Chives turn yellow for several reasons. Natural die-back in summer is the most common: chives naturally die back or yellow in midsummer heat, particularly in dry conditions, then recover and produce fresh growth in autumn. This is normal and does not indicate disease. Other causes of yellowing include: overcrowded clumps that have not been divided for several years (the bulbs in the centre become congested and struggle to grow); waterlogged soil (chives rot at the base in poorly drained positions); allium leaf miner damage; or nutrient deficiency in pots that have not been fed or repotted for several seasons.

How do I divide chives?

Chives benefit from division every 2 to 3 years to prevent the clump from becoming congested. Lift the entire clump in spring or autumn, tease it apart into smaller sections (each section should have 6 to 10 bulbs and healthy roots), and replant the sections 20 to 30 centimetres apart in fresh, well-composted soil. The original clump centre, which is often the least vigorous section, can be discarded. Division rejuvenates the plant, improves leaf quality and production, and can be used to create new chive plants for other parts of the garden or to share with other growers.

Can I eat chive flowers?

Yes. Chive flowers are edible and have a mild, onion-like flavour similar to the leaves but more delicate. The flowers can be used whole as a garnish on salads, soups, dips, and egg dishes. The individual florets can be separated and scattered over food for a more subtle appearance. Allowing chives to flower reduces leaf production as the plant directs energy into seed-setting; if maximum leaf harvest is the priority, cut off the flower stems as they appear. However, if edible flowers or the attractive purple globe flowers for ornamental use are desired, allow them to develop: they are also highly attractive to bees and other pollinators.