Geraniums are one of the most popular flowering plants grown in gardens and containers. Native to South Africa these cheerful bloomers brighten patios borders, and balcony gardens with their vibrant flowers and lush leaves.
But geranium leaves can change color from green to red, which can be scary for gardeners. Why do geranium leaves turn red, and what can you do about it?
Reasons for Reddening Geranium Foliage
There are several potential causes of red leaves on geraniums
1. Cool Temperatures
Geraniums thrive in warm weather and can suffer from shock when exposed to cool or fluctuating temperatures. This stress often turns their leaves red, especially in spring and fall when temperatures rise and dip. Container-grown geraniums are particularly prone as their roots are more exposed to temperature changes.
2. Overwatering
Red geranium leaves often turn brown because they have too much water. Geraniums prefer moderately moist, well-drained soil. When overwatered, their roots suffocate, unable to access oxygen. This puts stress on the plant, which could lead to leaves turning red and falling off.
3. Underwatering
While overwatering is more common, underwatering can also turn geranium leaves red. If the soil dries out too much between waterings, the plant becomes stressed. Leaves redden and wilt as the geranium struggles to absorb sufficient moisture.
4. Sunburn
Geraniums need a lot of sun, but they can get burned if there is too much light, especially on hot, sunny days. This shows up as reddish spots or burns on the leaves that are closest to the sun. Moving the plant to light shade prevents further sun damage.
5. Mineral Deficiencies
Lack of phosphorus and other minerals can keep geraniums from getting the nutrients they need to grow and do photosynthesis. This deficiency stress makes their older leaves turn red. Fertilizing with phosphorus-rich plant food restores health.
6. Diseases
While less common, fungal diseases like leaf rust can cause red/brown lesions on geranium foliage. These develop as spots on leaf undersides rather than the whole leaf reddening.
Solutions for Red Geranium Leaves
Now that we’ve covered the reasons behind reddening geranium foliage, let’s discuss solutions to restore their normal, vibrant color:
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Adjust watering – Check soil moisture before watering and only water when the top 1-2 inches become dry. Empty excess water from saucers after 30 minutes. This prevents over and underwatering.
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Move containers – Bring potted geraniums indoors or under cover during cold snaps and temperature drops. This protects their roots from chill damage.
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Provide shade – Filter sunlight with sheer curtains or move containers to a spot with light afternoon/midday shade. This prevents sunburn.
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Fertilize regularly – Feed every 2-4 weeks with a balanced liquid fertilizer or slow-release granular plant food. This prevents nutrient deficiencies.
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Prune affected leaves – Remove any leaves which are entirely red to promote new healthy growth. Make cuts just above the leaf joints with clean shears.
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Treat diseases – If fungal leaf spots are present, apply suitable organic fungicides like neem oil, sulfur, or copper soap. Always follow label directions.
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Repot annually – Refresh potting mix and increase container size every spring so roots have room to grow. Use porous soil and add drainage material.
With proper site selection, watering, fertilization, and care, geranium foliage will remain lush and green all season long. Red leaves are usually an easy fix. Just diagnose the cause and implement solutions to restore your geraniums to colorful health. With a bit of attention, you can enjoy these classics for years to come.
Frequently Asked Questions about Red Geranium Leaves
To summarize key points about reddening geranium foliage, here are answers to some common questions:
Why are my geranium leaves turning red?
The main causes of red geranium leaves are cool temperatures, overwatering, underwatering, sunburn, mineral deficiencies, and diseases. Identify the cause and adjust care accordingly.
Should I remove red leaves from my geraniums?
Yes, pruning off fully red or mostly red leaves promotes new healthy growth. Make clean cuts just above the joints using sterilized pruning shears.
How can I prevent red geranium leaves?
Proper planting site, attentive watering, fertilization, pruning, and disease management prevents almost all cases of reddening geranium foliage.
Are red leaves bad for geraniums?
Red leaves mean the plant is stressed. While not immediately fatal, long-term stress weakens geraniums and makes them prone to decline. Address the cause before extensive leaf loss occurs.
What deficiencies cause red geranium leaves?
Lack of phosphorus and other nutrients due to insufficient fertilizer can lead to red geranium foliage. Apply a balanced plant food every 2-4 weeks.
Should I bring geraniums with red leaves indoors for winter?
No, it’s best to discard stressed geraniums with extensive leaf reddening before overwintering. Start fresh with vigorous new plants the following spring.
By understanding what makes geranium foliage turn red and taking prompt action, you can restore their vibrant color and keep these classics flourishing. With the right care, geraniums will thank you with endless flowers and foliage all season long.
Why are my geranium leaves turning red?
Geranium leaves can turn red for a variety of reasons, including:
- Not enough water: Red leaves may mean the plant is stressed by drought Remove the top 3 to 5 cm of soil. If the soil is dry, the geranium needs water, which could be why the leaves are turning red. Hand-water the geranium deeply, and add some wetting agents to help the water get into the soil. Use Seasol to help the plant get over its stress. (This product is great for helping with heat stress. It works best when used before the stress, but it can also be used during or after a heat wave.) ).
- Because of their genes, some types of geraniums naturally have leaves that are red or bronze in color. If this is true, the leaves turning red is normal and nothing to worry about.
- Sun exposure: Geraniums do better in full sun than in partial shade. If they are in direct sunlight for a long time, the leaves can turn red. That’s just how the plant protects itself from sun damage, and it won’t hurt the plant.
- Temperature: Geraniums do best in temperatures between 60°F and 75°F (15°C and 24°C). If they are exposed to very hot or cold temperatures, the leaves may turn red. This means the plant is stressed, so you should either move it to a better spot or protect it from dangerously high or low temperatures.
- Disease: Leaves that are red can also be a sign of a fungal or viral disease, like powdery mildew, botrytis, or verticillium wilt. If you see any other signs, like leaves wilting, turning yellow, or turning brown, you should see a doctor right away to get a diagnosis and treatment.
- Lack of Nutrients: Geraniums need certain nutrients to grow and bloom. If they don’t get enough of these nutrients, the leaves may turn red. This could be because the soil isn’t fertilized enough or isn’t good enough.
It’s important to remember that you should always look for other signs, like leaves wilting, turning yellow, or turning brown, so you can figure out what’s wrong and fix it.
Growing geraniums in the ground:
- Benefits: Geraniums that are planted in the ground have bigger roots that let them get more water and food. They also get help from rain, which can cut down on the need to water them. When geraniums are planted in the ground, they can grow deeper roots that can help them survive dry times.
- Cons: Some people can’t plant a geranium in the ground because they don’t have enough room, so they have to plant it in a pot.
In conclusion, Geraniums can be grown in pots or in the ground, and the best option depends on your personal preference and the conditions of your garden. Geraniums grown in pots are easy to move around and can be placed in different locations, but they will dry out faster and will need to be watered more frequently. Geraniums planted in the ground have a larger root system, and can establish deeper roots, but they are more affected by the soil and weather conditions and can be difficult to move around.