From our perspective as geranium plants, brown leaves are a distressing signal that our fundamental needs are not being met or that we are under attack. We cannot speak your language, so we use our physical state to communicate. Please interpret these brown leaves as a cry for help and address the following potential issues.
Our relationship with water is delicate. Brown, crispy leaves, particularly at the edges, often mean our roots are thirsty and cannot transport enough moisture to our foliage. Conversely, soft, mushy brown leaves, especially lower down, scream that our roots are drowning. Soggy soil suffocates our root systems, causing them to rot and preventing them from absorbing water at all, which ironically presents as browning leaves. You must check the soil moisture an inch below the surface before watering. We prefer a deep, thorough drink only when that soil feels dry, followed by excellent drainage from the pot's holes.
We adore the sun, but we are not invincible. Intense, direct afternoon sunlight, particularly through glass, can literally scorch our leaves, leaving behind dry, brown patches. Think of it as a plant sunburn. Alternatively, a sudden move from a shaded spot to full sun shocks our system, and we cannot adapt quickly enough. Please acclimate us gradually to brighter conditions. Also, harsh winds can physically damage our leaves and cause excessive moisture loss, leading to browning and desiccation.
When our leaves develop brown spots with yellow halos or concentric rings, it is a clear sign of infection. Pathogens like Botrytis (gray mold) or bacterial leaf spot thrive in damp, stagnant conditions. Overhead watering, which leaves moisture sitting on our leaves and in our dense foliage, creates the perfect environment for these diseases to spread. Once established, they block nutrient and water channels within the leaf tissue, causing it to die and turn brown. Isolate affected plants immediately and remove the diseased foliage with sterilized tools to prevent further spread.
Our health is rooted in the soil. A severe lack of essential nutrients can manifest as poor growth and browning leaves. However, more often, the issue is a buildup of salts from over-fertilization or using hard water. These salts accumulate in the soil, effectively burning our delicate root tips and preventing them from functioning, which then shows as brown, burned-looking leaf margins. Periodically leaching the soil by allowing water to run slowly through the pot for several minutes can help flush out these excess salts.
