Curling rose leaves nearly always signal that something is actively stressing the plant, whether that is a pest feeding on the foliage, a disease spreading through the tissue, or an environmental problem like extreme heat or drought. The good news is that the pattern of curling, combined with a few other visual clues, usually points you toward the specific cause. Downward curling, upward cupping, distorted new growth, and full leaf rolls each suggest different culprits, and the fixes range from a blast of water to removing the entire plant.
Aphids and Thrips
Sap-sucking insects are the single most common reason rose leaves curl, and aphids top the list. These tiny, soft-bodied insects cluster on the undersides of new leaves and along tender stems, draining fluid and injecting saliva that causes the tissue to pucker and curl downward. You will usually spot them easily: green, pink, or black clusters at shoot tips, often accompanied by a sticky residue (honeydew) and sometimes by ants that feed on it. A strong jet of water from a hose knocks most aphids off, and repeating that every couple of days for a week or two usually breaks the cycle. For heavier infestations, insecticidal soap or neem oil sprayed directly on the insects works well.
Thrips are harder to see but leave distinct marks. These slender insects rasp the surface of leaves and petals, feeding on the contents of individual cells. On roses grown in open fields, thrips feeding on young flushes causes scarring, yellow blotches, brown streaks, and upward curling of leaves; damage during bud formation can produce malformed buds that open incompletely or not at all.1Oxford Academic (Journal of Integrated Pest Management). Widening range of thrips in open-field rose cultivation: three species newly identified as pests in southern India If you suspect thrips, tap a flower or shoot tip over a white sheet of paper. The tiny, elongated insects will fall and begin crawling, and you can see them against the white background. Blue or yellow sticky traps near the plant help monitor numbers, and spinosad-based sprays are effective against thrips without harming most beneficial insects.
Spider Mites
When rose leaves develop a stippled, bronzy look and curl slightly upward before dropping, spider mites are the likely suspect. These are not true insects but arachnids, barely visible without magnification. They thrive in hot, dry conditions, which is why outbreaks tend to spike in midsummer. Fine webbing on the undersides of leaves or between leaf clusters is the telltale sign. By the time webbing is obvious, the population is already large.
Spider mites reproduce fast in dry heat, so the first line of defense is increasing humidity around the foliage. Overhead watering or misting the undersides of leaves disrupts their environment. Horticultural oil or insecticidal soap smothers them on contact, but you need thorough coverage of the leaf undersides and repeated applications about a week apart. Avoid broad-spectrum insecticides like pyrethroids for mite control: they kill the predatory insects that naturally keep mite populations in check, often making the problem worse within a few weeks.
Rose Rosette Disease
If new growth on your rose looks dramatically distorted, with an unusual reddish color, excessive thorniness, and a bushy cluster of shoots sometimes described as a “witches’ broom,” you may be dealing with rose rosette disease. This viral disease, caused by rose rosette virus (RRV), has been spreading across the United States and Canada since the 1940s and is considered a serious emerging threat to rose cultivation in Europe as well.2Plant Pathology. Facing Rose rosette virus: A risk to European rose cultivation Characteristic symptoms include deformed leaves, abnormal thorns, and those distinctive witches’ brooms.3Plant Health Progress. Rose Rosette Disease: A Diagnostic Guide
RRV is transmitted by an eriophyid mite called Phyllocoptes fructiphilus, which is so small you cannot see it without magnification. The mite can establish populations, lay eggs, and develop through all life stages on every rose variety tested so far.4Plant Pathology. Transmission attributes and resistance to rose rosette virus The virus can also spread through grafting. There is currently no cure. Once a rose is infected, it should be removed entirely, including as much of the root system as possible, bagged, and discarded (not composted). Leaving an infected plant in the garden puts every nearby rose at risk, since the mites carrying the virus travel on wind currents.
Rose rosette is sometimes confused with herbicide damage or normal spring reddening of new growth. A key difference: herbicide damage tends to affect all new growth uniformly, while rose rosette often starts on one cane or section of the plant before spreading. The excessive thorn production and extreme shoot proliferation are fairly unique to this disease. If you are uncertain, your local cooperative extension office can help with diagnosis, and some labs offer molecular testing for the virus.
Powdery Mildew
Powdery mildew is one of the most recognizable rose diseases. It shows up as a white or grayish powdery coating on leaves, buds, and young stems. Affected leaves often curl, twist, or become distorted as the fungal tissue spreads across the surface and draws nutrients from the plant. The disease is caused by Podosphaera pannosa and is especially common in greenhouse-grown roses, where it can cause serious economic losses.5Plant Pathology. Silicon induced resistance against powdery mildew of roses caused by Podosphaera pannosa
Unlike many fungal diseases, powdery mildew does not need free water on the leaf surface to infect. It thrives in warm days with cool, humid nights, which is why it often appears in spring and fall rather than the hottest part of summer. Good air circulation is your most important preventive measure: prune to open up the center of the bush so air moves through freely, and avoid planting roses in tight, shaded corners.
For treatment, remove and discard visibly infected leaves. Fungicide sprays work best as a preventive rather than a cure. Research into alternative controls has shown promise: phosphates, carbonates, and horticultural oils all offer some degree of control against foliar diseases on roses.6ISHS Acta Horticulturae. II International Rose Symposium: DISEASES OF ROSES: EVOLUTION OF PROBLEMS AND NEW APPROACHES FOR THEIR CONTROL A common home remedy is a dilute baking soda spray (sodium bicarbonate), which raises the leaf surface pH enough to inhibit the fungus. Commercial potassium bicarbonate products work on the same principle and tend to be somewhat more effective. Neem oil also has fungicidal properties and can double as a pest deterrent.
Heat Stress and Underwatering
Roses are fairly heat-tolerant, but during prolonged stretches above about 95°F (35°C), leaves often curl inward as a self-protective response. The plant reduces its exposed leaf area to slow water loss from transpiration. This curling tends to be uniform across the plant, affecting older and newer leaves roughly equally, and the leaves themselves look otherwise healthy: no spots, no discoloration, no pests. They may feel dry or papery to the touch.
Underwatering produces a similar look and often compounds heat stress. Roses need deep, consistent moisture, especially during hot weather. A good rule of thumb for established bushes in the ground is about an inch of water per week in moderate weather, and substantially more in heat. Container roses dry out even faster and may need daily watering in summer. If you are watering regularly but the plant still looks stressed, check whether the soil is actually absorbing the water. Compacted clay or bone-dry potting mix can repel water, sending it down the sides of the root zone without wetting the interior. Mulching with two to three inches of organic material (wood chips, shredded bark, or compost) slows evaporation and keeps roots cooler.
Overwatering, less commonly discussed, can also contribute to leaf curling if it leads to root damage. Waterlogged soil suffocates roots, reducing their ability to take up nutrients and water. The plant responds much as it would to drought, with wilting and curling leaves, even though the soil is soaking wet. If the soil stays soggy for days after watering, improve drainage before adding more water.
Herbicide Drift
Roses are remarkably sensitive to certain herbicides, and damage from herbicide drift is more common than many gardeners realize. Products containing 2,4-D, dicamba, or triclopyr, often used on lawns to kill broadleaf weeds, can vaporize or drift on the wind and settle on nearby roses. Even tiny amounts cause dramatic leaf distortion: cupping, twisting, elongated and strap-like leaves, and thickened, rubbery stems. The damage typically appears on new growth within a few days of exposure.
Herbicide-damaged leaves look different from pest or disease damage. The distortion is usually symmetrical and affects all new growth at once, without spots, webbing, or insect bodies. Leaf veins may appear abnormally prominent and the tissue between them puckered. If you or a neighbor recently applied a broadleaf weed killer, especially on a warm or breezy day, herbicide drift is a strong possibility.
There is no treatment for herbicide-damaged tissue. The good news is that most roses recover if the exposure was a one-time event. Remove the worst-affected growth if it bothers you, keep the plant well watered and fed, and new growth should come in normally. Repeated or heavy exposure can kill a rose, though. If you need to use broadleaf herbicides near roses, apply them on calm, cool mornings, use amine formulations rather than ester formulations (which volatilize more easily), and keep the spray nozzle low to the ground.
Nutrient Problems
Nutrient deficiencies and imbalances occasionally cause leaf curling, though they are less common than pest or environmental causes. Calcium deficiency is one example: research on cut roses found that low calcium levels led to necrosis and abscission (dropping) of older leaves, and also increased susceptibility to fungal infection by Botrytis cinerea.7ISHS Acta Horticulturae. CUT ROSE QUALITY AS AFFECTED BY CALCIUM SUPPLY AND TRANSLOCATION In garden settings, calcium deficiency is uncommon in neutral to slightly acidic soils but can show up in very acidic or very sandy soils where calcium leaches away.
Iron deficiency, which shows up as yellowing between leaf veins (interveinal chlorosis) on new growth, can sometimes be accompanied by slight curling. This is usually a soil pH problem rather than a true absence of iron: when soil pH climbs above about 7.0, iron becomes chemically unavailable to plants even if it is present in the soil. A soil test is the most useful diagnostic step here. If pH is too high, sulfur amendments bring it down over time. If pH is fine but the plant still looks deficient, a chelated iron drench around the root zone provides a faster fix.
Excess nitrogen, often from enthusiastic fertilizing, pushes lush, soft growth that is more attractive to aphids and more vulnerable to fungal diseases. The new leaves may appear oversized, curled, and darker green than normal. The solution is to pull back on high-nitrogen fertilizers and let the plant balance itself. A slow-release, balanced rose fertilizer applied according to the label is almost always preferable to frequent high-nitrogen feeds.
Leaf-Rolling Sawflies
If individual leaves are rolled tightly into neat tubes or cylinders, the culprit may be a leaf-rolling sawfly rather than a disease or environmental stress. The adult sawfly, a wasp-like insect, lays eggs on the leaf edge, and the chemical she injects during egg-laying causes the leaf to roll around the developing larva, providing it shelter and food. The rolled leaves are distinctive: they look deliberately wrapped, almost like tiny cigars, and if you carefully unroll one you may find a small, pale green caterpillar-like larva inside.8J-STAGE. Distribution, Immature Stages and Life History of a Rose Leaf-rolling Sawfly, Pamphilius hilaris, in Japan (Hymenoptera, Pamphiliidae)
Sawfly damage is mostly cosmetic. Unless a large proportion of the bush is affected, the plant’s health is not seriously threatened. Picking off rolled leaves by hand and discarding them (not onto the compost pile) is the simplest control method. Systemic insecticides are overkill for this problem and risk harming pollinators. If sawflies are a recurring annual issue, a dormant-season cleanup of fallen leaves and debris helps reduce overwintering pupae.
How to Narrow Down the Cause
Faced with curling leaves, start with the simplest checks and work outward:
- Look for pests first. Turn over several curled leaves and examine the undersides. Aphids, thrips, and spider mites are all visible with the naked eye or a basic hand lens. Webbing means mites. Sticky residue means aphids. Silvery streaks or stippling on the leaf surface means thrips.
- Check the pattern. Curling on only new growth suggests aphids, herbicide drift, or rose rosette disease. Curling throughout the plant, including older leaves, points more toward heat stress, drought, or root problems. Rolled individual leaves in tidy tubes suggest sawflies.
- Look for secondary symptoms. White powdery coating means powdery mildew. Distorted, reddened shoots with excessive thorns mean possible rose rosette. Yellow blotches and brown streaks mean thrips. Clean, otherwise healthy-looking leaves that are just curling inward suggest environmental stress.
- Consider recent events. Did someone spray a lawn herbicide nearby? Has it been unusually hot or dry? Did you recently change your fertilizing routine? Timing often reveals the cause faster than close inspection of the leaves themselves.
Researchers are developing tools to make plant diagnosis more accessible. A recent study demonstrated a mobile phone application using deep learning models that could identify rose diseases and pests from photographs with about 95% accuracy.9DergiPark (Journal of Agricultural Sciences). Mobile Device-Based Detection System of Diseases and Pests in Rose Plants Using Deep Convolutional Neural Networks and Quantization These tools are not yet widely available in consumer-friendly form, but they signal that phone-based plant diagnosis is coming and may eventually be a standard part of gardening.
Choosing Varieties That Resist Common Problems
If you are planting new roses or replacing one that succumbed to disease, variety selection can save you a lot of trouble. Susceptibility to powdery mildew, for example, varies dramatically between cultivars. Field studies comparing rose varieties have found that some, like “Carefree Wonder,” show high resistance to powdery mildew, while others, like “Red Cap,” are highly susceptible under the same growing conditions.10ScienceDirect. Modeling and temporal analysis of electrical impedance spectroscopy responses of Rosa chinensis under powdery mildew stress The difference between a resistant and susceptible variety can mean the difference between occasional cosmetic issues and a constant battle with fungicide sprays.
Disease-resistant breeding programs have produced entire lines of roses marketed for their toughness. The Knock Out series, Earth-Kind roses, and the Canadian Explorer series are all bred for reduced susceptibility to black spot and powdery mildew, though none are completely immune. Planting these in good conditions, meaning full sun, well-drained soil, adequate spacing for air flow, and consistent watering, gives them the best chance to shrug off the problems that cause leaf curling in less resilient varieties. No variety is pest-proof, and even the toughest rose can develop problems in poor conditions, but starting with a resistant cultivar tilts the odds heavily in your favor.
For rose rosette disease specifically, no commercially available variety has shown reliable resistance. The eriophyid mite vector has been found capable of colonizing every genotype tested.4Plant Pathology. Transmission attributes and resistance to rose rosette virus This means that diversity in the garden, mixing roses with other shrubs rather than planting long monoculture hedges, is currently the best landscape-level strategy for slowing the spread of RRV. Multiflora rose, an invasive species in much of the eastern United States, is a major reservoir for the virus, so removing it from nearby areas helps protect cultivated roses.