Geranium Leaves Turning Brown – Common Plant Care Issue

Seeing geranium leaves turning brown is a common plant care issue. It’s a clear sign your plant is stressed, but don’t worry—it’s usually fixable. This guide will help you figure out why it’s happening and exactly what to do to bring your geraniums back to health.

Brown leaves can appear for many reasons. Sometimes it’s just a single leaf aging naturally. More often, it’s about water, weather, or disease. We’ll look at each cause and its specific solution.

Geranium Leaves Turning Brown

This section covers the primary reasons for browning leaves. Look closely at your plant’s pattern. Are the brown edges crispy or soggy? Are spots in the center or on the edges? Your observations are the first step to a cure.

1. Watering Problems: Too Much or Too Little

Incorrect watering is the top culprit. Geraniums prefer to dry out a bit between drinks.

• Overwatering (Wet, Soggy Brown): This causes root rot. Leaves turn yellow first, then develop soft, mushy brown spots or edges. The soil will feel constantly wet.
• Underwatering (Dry, Crispy Brown): Leaves get dry, crispy brown edges that may curl. The entire plant may wilt. Lower, older leaves often brown first.

How to Fix Watering Issues:

1. Check soil moisture by sticking your finger an inch deep. Water only if it’s dry.
2. Ensure your pot has excellent drainage holes. Never let the pot sit in a saucer of water.
3. Water deeply until it runs out the bottom, then empty the drainage tray.
4. Adjust with seasons: water less in cool, cloudy weather; more in hot, sunny periods.

2. Fungal Diseases: Leaf Spot and Rust

Fungal issues are a frequent cause of brown spots rather than overall browning.

• Leaf Spot: Small, circular brown spots that may have a yellow halo. They can merge into larger patches.
• Geranium Rust: Starts with pale yellow spots on top of leaves. You’ll see brown, rusty pustules on the leaf undersides. Leaves eventually turn completely brown and drop.

How to Fix Fungal Diseases:

1. Immediately remove and discard all affected leaves. Do not compost them.
2. Improve air circulation. Space plants apart and avoid crowding.
3. Water at the soil level, keeping leaves dry. Avoid overhead watering.
4. For severe cases, apply a fungicide labeled for use on geraniums, following instructions carefully.

3. Sun Scorch: Too Much of a Good Thing

While geraniums love sun, intense, direct afternoon rays can scorch leaves. This is especially common after moving a plant outdoors in spring.

• Brown areas appear bleached or pale at first, then turn crisp and brown.
• Scorching occurs on the leaves facing the sun, typically on the top of the plant.

How to Fix Sun Scorch:

1. Provide afternoon shade during the hottest part of the day, especially in summer.
2. Acclimate plants slowly when moving them to a sunnier location over 7-10 days.
3. Trim off the badly scorched leaves; they won’t recover.

4. Nutrient Deficiencies: Hungry Plants

A lack of key nutrients can cause leaf margins to brown.

• Potassium deficiency often shows as browning or yellowing on leaf edges and tips.
• It’s often combined with poor flowering.

How to Fix Nutrient Issues:

1. Feed your geraniums regularly during the growing season (spring to early fall).
2. Use a balanced, water-soluble fertilizer or one formulated for flowering plants.
3. Follow the package directions—over-fertilizing can also cause browning and damage roots.

5. Environmental Stress: Heat and Cold

Extreme temperatures shock plants.

• Heat Stress: Combined with low humidity, high heat can cause overall browning and crisping.
• Cold Damage: Exposure to frost or chilly drafts causes dark, water-soaked brown patches. Leaves may become mushy.

How to Fix Environmental Stress:

1. Protect plants from sudden temperature changes.
2. Bring potted geraniums indoors before the first fall frost.
3. In heatwaves, provide extra water and temporary shade.

6. Pests: Insects Causing Damage

Some pests suck sap, leading to brown, stippled, or distorted leaves.

• Aphids & Spider Mites: These tiny pests cause yellow stippling that can turn brown. Look for fine webbing (mites) or clusters of small insects.
• Caterpillars: Chew irregular holes and edges, leaving brown, damaged tissue behind.

How to Fix Pest Problems:

1. Spray plants with a strong jet of water to dislodge aphids and mites.
2. Apply insecticidal soap or neem oil, covering all leaf surfaces, especially undersides.
3. Pick off caterpillars by hand if possible.

Step-by-Step Diagnosis Guide

1. Check the Soil: Is it sopping wet or bone dry? This points to watering.
2. Inspect the Leaves: Look at the pattern. Crispy edges? Likely underwatering. Soft spots? Likely overwatering or disease. Distinct spots? Likely fungal.
3. Consider the Season: Is it a heatwave or did an early frost hit? Think about environmental causes.
4. Look Closer: Examine the underside of leaves for pests or rust pustules.
5. Review Your Care: When did you last fertilize? Did you recently move the plant?

Prevention is the Best Cure

Keeping your geraniums healthy stops problems before they start.

• Use well-draining potting mix. A mix for containers is essential.
• Choose pots with drainage holes every single time.
• Place in a location with at least 4-6 hours of sunlight, with some protection from harsh afternoon sun.
• Water and fertilize on a consistent schedule based on the plant’s needs, not the calendar.
• Deadhead spent blooms and remove any unhealthy leaves promptly to improve air flow.

When to Start Over

Sometimes, a plant is too far gone, especially with severe root rot. If the main stems are mushy and brown at the base, it’s best to discard the plant. However, you can often take healthy stem cuttings to propagate a new, disease-free plant. It’s a simple way to save your favorite variety.

FAQ: Geranium Leaves Turning Brown

Should I cut off brown leaves on my geranium?
Yes. Prune off brown leaves with clean shears. This improves appearance and prevents disease from spreading. It also helps the plant focus energy on new, healthy growth.

Can a geranium recover from brown leaves?
The brown parts will not turn green again. But the plant can recover fully if you correct the underlying problem. New growth will be healthy if conditions are right.

Why are my geranium leaves turning brown after repotting?
This is often transplant shock. The roots were disturbed. Ensure you didn’t plant too deeply and keep the soil evenly moist (not soggy) as it adjusts. It should bounce back.

What does an overwatered geranium look like?
Leaves turn yellow, then get soft, mushy brown areas. The plant may wilt despite wet soil, and stems may feel soft. A musty smell from the soil is another clue.

Is it normal for bottom leaves to turn brown?
A few lower leaves turning brown and falling off as the plant grows is normal. If it’s many leaves or spreading upward, it’s a sign of stress from water, light, or nutrients.

By understanding why your geranium leaves are turning brown, you can take quick, effective action. Start with the simplest fix—checking your watering habits—and work through the list. With a few adjustments, your geraniums will be thriving again, covered in green leaves and bright blooms.