How to Identify Issues with Your Rose Plants

Every rose gardener dreams of full, vibrant blooms against a backdrop of lush, green foliage. So when those blooms fade and leaves yellow, it can be cause for concern. No need to worry: this post will provide a step-by-step diagnostic flow and symptom atlas to determine if your roses’ issues are nutritional, pest/disease-related, or environmental , and what you can do to solve them.

Quick Diagnostic Flow

First, ask yourself if there have been any recent changes in your roses’ environment. These changes could include:

Recent weather (such as heatwaves, frost, or strong winds)
Watering changes
Fertilizer use
Transplanting/repotting

Next, consider the overall look of your roses. Check for things like:

New vs. old growth: New growth is more sensitive to environmental and nutritional changes, while old growth is more susceptible to pests and disease.

Uniform vs. patchy symptoms: If the symptoms are uniform and gradual, the issue is likely nutrition or environment-related. If you see patchy spots that are spreading or leaf distortion, your roses may have a fungal infection or pest infestation.

Sudden wilting or dieback: If there’s been heavy rain or extreme temperatures, there could be an underlying root issue.

One plant vs. multiple: If a single rose is showing symptoms, there may be a nutrient imbalance or environmental issue. If multiple roses are showing the same symptoms, there’s likely a pest or disease problem.

Tools for Diagnosis (What to Use)

Luckily, we have a range of tools and technology to help us identify issues with our roses. These include:

Hand lens (pests/spores): Many pests and diseases are too small to be seen by the naked eye. A hand lens gives you a clearer look and helps identify the problem.
White paper tap test (thrips/mites): Hold a sheet of white paper underneath the part of your rose you suspect is infected. Gently tap the leaves or bud, and look for little moving specks that have fallen onto the paper.
Moisture meter/finger test: If you’re unsure if you’re over/under-watering your roses, quickly check the soil with a moisture meter or your finger. If the soil feels wet, ease up on the watering. If it feels dry, your roses are probably thirsty.
pH/soil test: Nutritional deficiencies are often caused by a high pH level of the soil. Roses do best in soil with a pH of 6.5-7.0.
Clean pruners: Essential for removing and disposing of any infected foliage to avoid the spread of disease.
Notebook/app for symptom log & photos: Symptom tracking is key to proper diagnosis and treatment. Record your findings so you have an accurate picture.

Leaf Symptom Atlas: What Patterns Mean

Signs of underlying issues with roses often manifest on the leaves. The problem lies within the pattern. Look closely, and you should be able to identify and troubleshoot effectively.

Yellowing (Chlorosis) Patterns

If the foliage on your roses is turning yellow, it could be an indication of watering issues, nutrient deficiencies, or temperature stress. Look for:

Whole leaf yellowing (beginning with older leaves): A sign of a nitrogen deficiency, lack of fertilizer, or overwatering/poor drainage.
Interveinal yellowing (new leaves) with green veins: A sign of an iron deficiency due to high soil pH.
Interveinal yellowing (older leaves): A sign of a possible magnesium deficiency.
Mottled yellow & stippling (upper leaf surface) with fine webbing underside: An indication of the presence of spider mites – which can worsen with drought or extreme heat.

*Take note of which leaves are affected (old or new), check for soil moisture, and record any recent feedings.

Spots, Blotches, and Marginal Burn

These symptoms are a strong indication that your roses are dealing with one of the common fungal infections or leaf scorch. Look for:

Round black spots & yellow halos with falling leaves: A sign of black spot.
White powdery film: A sign of powdery mildew – especially if days have been dry and nights have been cool.
Tan/brown margins: “Scorch” is caused by underwatering, salt buildup, or hot wind. Ensure your potting mix or soil is well-draining and retains moisture.

Distortion, Curling, Silvering

These symptoms hint at a possible pest infestation or rare disease. Look for:

Silvery/bronze sheen with deformed buds: A sign of thrips.
Tight curling/clustered aphids on new tips, sticky honeydew: A sign of aphids.
Uniform silver on one cane, later dieback: An indication of silver leaf disease – although rare. Read on to the “Canes/Stems” section for more information.

Buds & Blooms: If Flowers Are the Clue

If your roses aren’t blooming as vibrantly as you imagined, check for these symptoms:

Dry buds that fail to open: “Bud blast” is a sign of drought/heat stress, thrips, severe nutrient imbalance (low potassium), or sudden root disturbance.
Deformed blooms/browned petal edges: An indication of thrips or dehydration from high heat/low humidity.
No blooms at all: There could be many reasons why your roses aren’t blooming – including insufficient sunlight, lack of fertilization, and improper pruning timing.

Canes & Stems: Structural Signals

Hints of an underlying health issue can also be found on the canes of your roses. Look for:

Blackened lesions & cane dieback: A sign of canker – a fungal infection that eats away at the canes. Cut 2-3 inches below damaged wood into green tissue, and be sure to sterilize any tools used.
Shoots of different blooms or foliage: These “graft suckers” can drain your rose’s energy. Cut them off cleanly at their base.
Silvered cane & branch dieback: A strong sign of silver leaf disease. Prune and dispose of infected branches and sanitize tools thoroughly. Avoid pruning in wet weather conditions.

Roots & Soil: The Hidden Causes

Strong roots and healthy soil are essential to thriving roses. Keep an eye out for:

Chronic wilt (despite watering): A sign of root rot if accompanied by brown roots and a sour smell, or rootbound containers for potted roses.
Moisture buildup on soil surface: A sign of poor soil structure or compaction. Improve drainage by amending the soil with organic material – such as perlite or vermiculite.

A simple soil test will tell you exactly what your roses need. Things to look for in a soil test include:

High pH: If your soil has a pH above 7.5, your roses could be suffering from an iron deficiency.
Low organic matter: A common cause of nutrient imbalance.
Salt buildup: A sign of overfertilization. Use slow-release fertilizers and follow the instructions on the packaging.

Environmental Stress Read-Through

There are a few weather-related events that will inevitably pose challenges to the health of your roses. But with a little help from you, it’s nothing they can’t bounce back from! Be aware of:

Heatwaves: High summer temperatures can lead to dehydration and sun scorch. Look for brown, crispy patches on the foliage and exposed bud tips. Water deeply and infrequently at the base of the plant – preferably in the early mornings.
Cold/frost: Late cold snaps can damage new growth. Look for blackened wood and prune back to a healthy bud.
Strong winds: Look for tattered leaves and desiccated buds. Consider staking your roses or creating a temporary windbreak structure.

*If you see petals suddenly drooping after moving or repotting your roses, they may be suffering from transplant shock. Provide temporary afternoon shade and steady moisture, and they should bounce back in no time.

Nutrient Deficiency Guide (By Element)

Roses need a balanced diet with all the essential nutrients for an optimal quality of life. A quick soil test alongside close observation of stems and foliage will tell you which adjustments are needed to fix any deficiency. Always ensure your soil pH remains between 6.0-7.0.

Nitrogen (N)

Nitrogen is responsible for lush, green foliage. Without a sufficient amount, you’ll see a uniform yellowing/paling of older leaves and reduced flowering.

Action: Incorporate nitrogen-rich organic matter into your soil. Apply a slow-release, balanced fertilizer – avoiding quick, heavy doses in high temperatures.

Phosphorus (P)

Phosphorus is essential for strong root development. Low amounts can lead to purple/reddish discoloration, weak stems, and stunted growth.

Action: Add phosphorous-rich organic matter into your soil and adjust pH level.

Potassium (K)

A lack of potassium can cause yellowing/browning of older leaf margins, a burnt/scorched appearance, and poor bud quality.

Action: Apply a slow-release, potassium-forward fertilizer and adjust pH level.

Magnesium (Mg)

A magnesium deficiency will often cause interveinal yellowing of older leaves and reduced flowering.

Action: Raise soil pH with organic amendments. Add small amounts of Epsom salt ONLY if a magnesium deficiency is verified by a soil test. Overuse can harm your roses.

Iron (Fe)

Insufficient iron levels lead to interveinal yellowing on new leaves.

Action: Lower soil pH with organic amendments. Use chelated iron as a short-term fix alongside a balanced fertilizer.

Calcium (Ca)

A lack of calcium results in distorted new growth and browning/blackening of leaf tips.

Action: Provide stable moisture with consistent watering. Consider adding gypsum to the soil to prevent salt buildup.

Disease vs. Deficiency: How to Tell

When imperfections appear on the buds and foliage of your roses, it can be difficult to determine the root cause. Luckily, there are a few telltale signs to help you figure out whether the culprit is disease or deficiency.

If your roses are lacking essential nutrients, you may see:

Uniform patterns with older leaves being affected first
Slow onset
Improvement with corrected feeding and soil pH adjustment

If your roses are suffering from a fungal infection, you may see:

Distinct spots
Fuzzy or mildewy growth
Rings or lesions
Rapid spread from plant to plant
Leaf drop

Tidy up the area around your roses by removing and disposing of any fallen or infected leaves. Improve airflow by pruning out canes that are growing towards the center of the bush.

Still unsure if deficiency or disease is to blame? Here are a few extra clues that can help confirm the presence of a fungal infection:

Humidity history: If you live in a humid climate, your roses are more susceptible to disease.
Irrigation splash: Rain or overhead watering can splash fungal spores onto healthy foliage.
Dense canopy: Overgrown canopies can trap moisture and prevent airflow – increasing the risk of disease spread.
Presence of spores: Use a hand lens to check for fungal spores that are too tiny to be seen by the naked eye.

Pests at a Glance (Where and What to Check)

Roses are appealing not only to gardeners, but to a range of unwanted critters. Here are the most common pests that could be hindering your roses’ growth:

Aphids: Tiny, soft-bodied insects that cluster on tender bud tips. Check the leaves for honeydew (a sticky, sugary substance) and sooty mold (a black, powdery mold).
Spider mites: These often appear in hot, dry weather. Look for stippling (tiny white or yellow spots) on foliage and fine webbing undersides.
Thrips: Look for silvered petals/leaves with browned edges and deformed buds. Confirm the presence of thrips with the white paper tap test.
Sawfly/leafcutter: Leaves become “skeletonized” when these insects eat away at the tissue between the veins. They often chew only partway through the leaf – causing “windowpane” damage.

Pests are nothing to panic about. Many can be knocked off with a strong water jet or pruned/plucked off. If the infestation is severe, there are plenty of pesticide options. Always try organic methods before resorting to chemicals.

Our favorite method of prevention is companion planting – which attracts beneficial insects and wards off harmful ones.

Simple Tests & When to Test

Since the most common issues with rose plants are often brimming beneath the soil, there are a few quick ways to narrow down which one it might be:

Moisture check: Stick your finger in the soil to determine whether your roses need more or less water. You can also use a soil moisture meter for a more precise reading.
pH/soil test: Conduct a soil test annually or when chlorosis persists. This can help guide fertilizer choices to keep your roses on a well-balanced diet.
Fertilizer journal: Keep a record of the dates symptoms occur and how fast they progress. Also make note of which types of roses are experiencing which symptoms.
When to seek lab/help: When your roses are suffering from unexplained dieback or suspected viral/systemic issues, consider contacting your local county extension office for guidance.

Prevention Plan

There’s a fix for almost any underlying issue that could be going on with your roses, but prevention is always the best measure. Here are the steps you can take to reduce the risk of disease and keep them thriving:

Plant in a sunny location (6-8 hours per day) with adequate spacing between plants.
Prune in late winter or early spring with sparkling clean tools.
Water early in the morning at the base of the plant.
Mulch to improve soil quality and retain moisture.
Fertilize steadily. Go easy on the nitrogen.
Monitor for changes during seasonal shifts – such as heatwaves and cold snaps.

Nip Your Rose Issues in the Bud

Carefully monitor and take note of symptom patterns on your roses. Remember that most rose issues fall into 3 categories: deficiency, pests/disease, and environmental. A few simple tests will help you confirm which one your roses are suffering from and help you get to the bottom of it. Visit April & Ashley to browse our selection of premium rose bushes, shipped directly from our farm to your doorstep.