Rose Leaves Curling

Why rose leaves curl

Roses (Rosa spp.) are among the most widely grown garden plants, and curling leaves are one of the most common concerns rose growers bring to forums and garden centers. Unlike many plants where underwatering is the first thing to check, rose leaf curling is most often caused by pests, particularly aphids in spring and early summer and leafroller caterpillars through the growing season. Environmental causes including heat stress and herbicide damage also appear regularly. The pattern and location of the curling, combined with what is visible on the leaf surfaces, makes diagnosis straightforward in most cases. Here is what to look for.

Cause 1: Aphids

Signs: New growth and growing tips are curling downward and inward. Small soft-bodied insects are visible on the undersides of curled leaves and on stems near buds. The insects are typically green, pink, yellow, or black. A sticky, shiny residue (honeydew) may be on the leaves below, and black sooty mold may have developed on the honeydew. Ants may be climbing the canes. The damage is concentrated on the newest, most tender growth.

Why it happens: Roses are among the most aphid-prone plants in the garden. Aphids overwinter as eggs and hatch in spring to coincide with new rose growth. They cluster on soft new tissue, pierce it to feed on sap, and inject saliva that causes the leaf to curl down and inward around the colony, creating a protective environment. Populations can explode rapidly in warm weather, particularly if natural predators like ladybugs and parasitic wasps have been reduced by pesticide use.

Fix: Start with a strong jet of water to knock aphids off canes and leaves. A daily water blast for several days significantly reduces populations without chemicals. For heavier infestations, spray insecticidal soap or neem oil to both the upper and lower leaf surfaces, coating the curled leaves thoroughly. Repeat every 5 to 7 days for 2 to 3 applications. Avoid broad-spectrum insecticides that kill beneficial insects alongside the aphids. Encouraging ladybugs, lacewings, and parasitic wasps by avoiding pesticides provides longer-term control.

Cause 2: Rose leafrollers

Signs: Individual leaves are rolled lengthwise into a cylinder and held in position by fine silken threads. The rolled leaves may look like a small cigar or tube. Opening the roll reveals a small green, brown, or cream-colored caterpillar inside. Multiple leaves may be tied together in a bundle. The damage is scattered rather than concentrated on new growth only.

Why it happens: Several moth species produce larvae that roll and tie rose leaves as a feeding strategy. The most common in North America are the obliquebanded leafroller and the strawberry leafroller. The caterpillar rolls a leaf around itself to create a protected feeding shelter, cutting the leaf from the inside while remaining hidden from predators and contact sprays. Leafrollers are most active from late spring through summer and can produce multiple generations per year.

Fix: Hand-pick and destroy rolled leaves if numbers are manageable. Opening each roll and removing the caterpillar prevents it from completing its life cycle. For heavier infestations, apply spinosad or Bacillus thuringiensis (Bt) to the foliage when young caterpillars are active in spring before they roll into leaves. Once inside a roll, caterpillars are protected from most sprays. Timing treatment to the egg hatch period in early spring, before leaves are rolled, is the most effective approach.

Cause 3: Herbicide drift

Signs: The petioles (leaf stems) are twisting or curling in unusual ways, and leaves are distorting asymmetrically. Stems may be thickening or bending. New growth may be elongated and narrow. Multiple plants in the same area or downwind direction show similar symptoms simultaneously. The damage appeared suddenly, possibly after nearby lawn or agricultural herbicide application.

Why it happens: Roses are highly sensitive to broadleaf herbicides including 2,4-D, dicamba, and clopyralid, all of which are commonly used in lawn weed control. Even small amounts drifting from a neighbor's property on a warm, slightly windy day can produce dramatic distortion. The herbicides mimic plant growth hormones, causing uncontrolled cell elongation and the characteristic twisting and curling. Clopyralid can also persist in grass clippings used as mulch, reaching rose roots through the soil.

What to do: There is no chemical antidote. New growth emerging after the drift event may be normal if the exposure was light, and the plant may partially recover. Water the root zone to dilute any herbicide that settled in the soil. If clopyralid-contaminated mulch is suspected, remove it and replace with untreated material. Allow the plant several weeks to show whether recovery is occurring before making decisions about removal.

Cause 4: Heat stress and drought

Signs: Leaf edges are curling under on the hottest afternoons, particularly during heat waves. The curling relaxes overnight and the leaves look relatively normal in the morning. The soil is dry or inconsistently watered. The most affected leaves are on the most exposed parts of the plant. No insects are visible and no distortion is present.

Why it happens: Roses have moderate drought tolerance but high water demands during active growth and flowering. In peak summer heat, particularly above 90 degrees Fahrenheit, the leaves curl under to reduce their exposed surface area and slow water loss. This is a protective response, not permanent damage. Inconsistent watering that alternates between wet and dry conditions stresses the plant further and can contribute to other problems including black spot susceptibility.

Fix: Water deeply and consistently. Roses in the ground need approximately 1 to 2 inches of water per week during summer, more in hot climates. Apply a 2 to 3 inch layer of organic mulch around the base to retain soil moisture and keep roots cool. Water in the morning at the soil level rather than overhead to reduce fungal disease risk. Container roses may need daily watering in summer heat.

Cause 5: Rose mosaic virus

Signs: Yellow mottling, streaking, or ring spots appear on the leaves alongside curling or distortion. The patterns may be irregular and the leaf color looks uneven. Some canes may produce normal growth while others are clearly affected. The plant may be growing slowly. The symptoms are variable and often appear on some branches but not others.

Why it happens: Rose mosaic virus (RMV) is a complex of several viruses, most commonly Prunus necrotic ringspot virus and Apple mosaic virus, that are introduced through infected propagation material. Most commercial roses are grafted, and if the rootstock or scion was infected, the virus is present in the plant from the start. RMV does not spread from plant to plant in the garden; it travels only through propagation, grafting, or infected tools used for pruning. It does not kill roses but may reduce vigor and flowering somewhat.

What to do: There is no cure. Infected plants can be kept if they are performing acceptably. Remove severely affected canes with poor growth and disinfect pruning tools between cuts with diluted bleach or isopropyl alcohol. When purchasing new roses, buy from reputable nurseries that use virus-indexed propagation material. Avoid propagating from infected plants.

Frequently asked questions

Why are my rose leaves curling?

Rose leaves curl most commonly due to aphid infestation or rose leafroller caterpillars. Aphids cluster on the undersides of new growth and growing tips, causing the leaf edges to curl downward around the colony. A heavy infestation produces cupped, distorted new leaves covered in small soft-bodied insects that are often green, pink, or black. Rose leafrollers are caterpillars that physically roll the leaf lengthwise and fasten it with silk, creating a distinctive cigar-shaped leaf tube. Herbicide drift from nearby broadleaf herbicide applications causes asymmetric twisting and curling of stems and leaves, often with thickening of the petioles. Heat stress and drought cause the leaf edges to curl under on the hottest afternoons but typically recover by morning. Rose mosaic virus produces yellow mottling alongside curling and distorted growth.

Why are my rose leaves curling inward?

Rose leaves curling inward with small insects visible on the underside most commonly indicate aphids. Aphids feed by piercing young leaf tissue and sucking sap, and they inject saliva that causes the leaf to curl inward around them, creating a protected environment. The curling is most pronounced on new growth and growing tips, and the leaves may also be sticky from aphid honeydew or covered in sooty mold. Treat with insecticidal soap or neem oil applied to both leaf surfaces, or knock aphids off with a strong jet of water. If the leaves are curling inward and there are no insects visible, check for drought stress: rose leaves curl under on hot afternoons when soil moisture is low but typically return to normal the following morning when temperatures drop.

What are the rolled tubes in my rose leaves?

Rolled leaf tubes in roses are the work of rose leafroller caterpillars, most commonly the larvae of the obliquebanded leafroller moth (Choristoneura rosaceana) or the strawberry leafroller (Ancylis comptana). The caterpillar rolls a single leaf or several leaves together lengthwise and fastens them with silk, creating a protective tube to feed inside. The affected leaves are physically rolled and held in a cylinder shape; opening the tube reveals a small green or brown caterpillar. Hand-pick and destroy the rolled leaves if numbers are low. For heavier infestations, apply spinosad or Bacillus thuringiensis (Bt) when young caterpillars are active in spring before leaves are rolled.