Geraniums are popular flowering plants known for their vibrant blooms and diverse foliage. Gardeners often grow them in containers, hanging baskets, or garden beds, appreciating their low maintenance and long blooming season. Red coloration in their leaves is a common concern, indicating the plant may be experiencing stress. This article explores why geranium leaves turn red, whether this color change is reversible, and how gardeners can address the issue.
Why Geranium Leaves Turn Red
Red coloration in geranium leaves often signals environmental stress or nutrient imbalance. A common reason is exposure to cool temperatures, especially in spring or fall nights, which can shock these heat-loving plants below 55°F (13°C), leading to anthocyanin pigment production and a red hue.
Nutrient deficiencies frequently cause red leaves, primarily phosphorus deficiency. When phosphorus is lacking or its uptake is inhibited by cold soil, older, lower leaves may develop reddish or purplish discoloration. Magnesium deficiency can also contribute.
Improper watering, both overwatering and underwatering, can lead to red foliage. Overwatering causes roots to rot, impairing nutrient absorption, while underwatering stresses the plant. Geraniums prefer well-draining soil and tolerate drier conditions.
Beyond environmental factors, natural aging contributes to red leaves as older, lower leaves senesce. Some geranium varieties naturally develop red hues in their foliage as a normal part of their growth cycle. These genetic traits are not indicative of stress.
Can Red Geranium Leaves Revert to Green
Whether red geranium leaves can revert to green depends on the underlying cause and stress severity. If redness is due to temporary environmental stress, like a brief cold snap, new growth will likely emerge green. Slightly reddened existing leaves might slowly regain greenness once optimal conditions return.
However, if redness results from severe or prolonged stress, natural aging, or genetic predisposition, those specific red leaves will not turn green again. Leaves significantly changed in color or browning are unlikely to recover their original green pigmentation. The plant prioritizes energy toward new, healthy growth.
The primary goal of corrective action is to prevent new leaves from turning red and encourage vibrant, green foliage. While existing red leaves may persist, a healthy plant will produce new, unstressed leaves. Consistent care helps the plant thrive.
Addressing Red Geranium Leaves
Addressing red geranium leaves involves identifying the specific stressor and implementing cultural adjustments. Protecting plants from cold temperatures is a first step, especially outdoors. Bringing potted geraniums indoors or covering garden plants when temperatures drop below 55°F (13°C) can prevent cold-induced reddening.
Proper watering is important to prevent red leaves. Geraniums prefer their soil to dry out slightly between waterings; check moisture by sticking a finger about an inch into the soil. Avoid overwatering by ensuring pots have adequate drainage and not allowing plants to sit in standing water.
To address nutrient deficiencies, especially phosphorus, apply a balanced fertilizer for flowering plants. Fertilizers with an NPK ratio like 5-15-15 or 4-10-10 are often recommended. Regular feeding every 7 to 14 days helps ensure adequate nutrients.
Light adjustment is another consideration; while geraniums are sun-loving, intense, prolonged sun exposure can cause stress. If leaves turn red in strong sunlight, providing afternoon shade can be beneficial. Pruning severely affected or naturally aging red leaves encourages new, healthy green growth.