Hello, it is I, your geranium. I am trying my best to thrive and show you my beautiful blooms, but I am communicating a problem. The browning on my leaf edges is my distress signal. It is not a single issue but a symptom with several possible causes. To understand, you must think like a plant. Here is what might be happening from my perspective.
Water is my lifeblood, but its management is delicate. The most common reason for my crispy, brown leaf margins is a lack of water. My roots are not absorbing enough moisture to transport to my furthest parts—the leaf tips and edges. They dry out and die first. This could be due to infrequent watering, a root-bound pot where there isn't enough soil to hold water, or excessive heat speeding up evaporation. Conversely, if my soil is constantly soggy, my roots begin to suffocate and rot. Once damaged, these rotten roots cannot absorb water at all, leading to a paradoxical state of drought within me, also causing browning leaves, though often accompanied by yellowing and wilting.
You feed me to help me grow, but too much of a good thing is harmful. Synthetic fertilizers leave behind residual salts in the soil. Over time, these salts accumulate and create a high-concentration environment around my roots. This makes it physically difficult for me to take up water, a process called osmotic stress. The salts can also draw moisture directly out of my root cells. The resulting dehydration manifests as a brown "burn" specifically along my leaf edges and tips. You might even see a white crust on the soil surface or pot rim—this is the salt buildup.
While I am not a tropical plant, I still prefer a comfortable atmosphere. If I am placed near a heating vent, a radiator, or in a consistently hot and dry room, the excessive transpiration becomes a problem. I lose water through my leaves faster than my roots can replace it. The edges, being the most vulnerable, dry out and turn brown. This is especially common indoors during winter when heating systems drastically reduce ambient humidity.
My root system is my anchor and my mouth. If I have been in the same pot for too long, my roots may have exhausted the soil and become a tight, circular mass. This root-bound condition means water flows straight through the pot without being absorbed, leaving me thirsty. Furthermore, physical damage to my roots during transplanting can shock my system and impair their function. Until I can regenerate new roots, my leaves will show signs of stress, including browning edges, as I struggle to maintain hydration.
Sometimes, the issue is biological. Fungal diseases, such as Alternaria leaf spot or Botrytis blight, can cause browning on my leaves. However, this browning is often less uniform than the other causes; it may appear as distinct spots, lesions, or patches with concentric rings, rather than starting cleanly at the edges. It is frequently accompanied by yellow halos or a fuzzy gray mold, especially in cool, damp conditions with poor air circulation.
