It’s flowering season for geraniums and it’s easy to see why they are such popular plants in the garden. ‘But why do my geranium leaves turn red?’, you may ask.
Well, it’s a more common problem than you think and has a lot to do with simple watering mistakes.
“When geranium leaves start to turn red, it indicates that something is wrong and that the plant is under stress,” advises John Clifford, director of Gardenstone. “Although the bright red leaves look beautiful, it is crucial to address the problem to return the geranium to full health.”
So, if you already understood how to grow geraniums and are looking to solve this popular plant problem, you have come to the right place.
John Clifford is a director of Gardenstone, a leading UK-based garden landscaping retailer. With over 30 years in the gardening industry and ongoing work alongside The National Trust, John has built up a wide range of gardening and planting knowledge. Along with his youngest son, John has built a strong reputation for Gardenstone as a trusted source of high-quality garden products and expert gardening advice.
Why are my geranium leaves turning red?
If geranium leaves turn red, the plant is likely stressed.
The list of possible stressors is long, but we asked experts what the most likely suspects are.
1. Your geraniums are nutrient deficient.
“Geranium leaves change color when they lack nutrients,” says Monique Gudgeon, garden director of Sculpture by the lakes.
The missing nutrients are likely to be magnesium and phosphate, but fortunately there is a wide range of foods to counteract the deficiency.
“If you notice discoloration on your geranium leaves, be sure to water the plant and provide plenty of food,” advises Monique. “It’s important to remember that potted geraniums rely solely on you for water and nutrition; it’s best to water and feed them once a week.”
What you will need
Miracle-Gro Pour and Feed Liquid Plant Food, 1L
Fight nutrient deficiencies with this excellent all-rounder that your geraniums will love.
‘Storm Cloud’ Geranium Plant
Introduce this stunning variety into your garden, perfect for borders, balconies or patios.
Miracle-Gro Moisture Control Peat-Free Compost
This potting compost will feed your geraniums for up to three months and store and release water for your plants when they need it.
2. You are watering your geraniums too much
Overwatering is easy, and if you’re wondering if you can overwater plants in summer, the answer may surprise you.
“I recommend two heavy waterings per week, but be careful not to overwater as this can also affect the health of the plant,” advises John.
Knowing the signs of an overwatered geranium can help you make changes before it’s too late for the plant.
According to John, the symptoms are obvious: ‘When geraniums are overwatered, their leaves begin to turn limp and yellow. The roots will also start to rot.’
3. You are not watering them enough
On the other side of the coin, insufficient watering can be an alternative reason why geranium leaves turn red.
In some cases, red geranium leaves can be a sign of inadequate watering,” says John. ‘To rule this out, you can look for curling leaves and check at the base of your geranium. If the soil is dry, it might be a good idea to water the plant more regularly.’
Frequent questions
Why do my geranium leaves change color?
Yellow geranium leaves are another common problem with geraniums. In addition to watering errors, there is another likely culprit behind yellowing geranium leaves.
“Geranium leaves are likely to start changing color due to lack of sunlight,” explains Gardenstone’s John. “Geraniums are sun-loving plants, so they should be planted in an area of your garden in full sun and no shade.”
How can you tell the difference between an overwatered geranium and an underwatered geranium?
“If you stick your finger in the soil around your geranium and it’s dry, that’s usually a sign that it needs water,” says Monique of Sculpture by the Lakes. Plus, you can lift the pot and feel its weight. If it is noticeably clear, it may also mean that it is dry.’
“On the other hand, overwatered geraniums will have slimy roots and wet soil.”
You can also tell the difference between an overwatered geranium and an underwatered geranium by looking at the leaves.
“Overwatered geraniums can be identified by their yellow, limp leaves,” explains Gardenstone’s John. “Although irrigated geraniums may also have yellow leaves, they are likely to have curled edges rather than being limp due to their dry roots.”
Red geranium leaves are more common than you might think, but with a few changes to the way you care for your plants, you might be able to avoid the problem altogether.