Hello, it is I, your Grevillea. I am a resilient and sun-loving soul, but my brown leaf tips are my way of communicating that my needs are not being fully met. Do not be overly alarmed; this is a common language we plants speak. Let me explain the potential reasons from my perspective.
This is the most frequent conversation we need to have. I am a native of well-drained Australian soils and am particularly sensitive to certain minerals. The water you provide, especially if it is tap water, often contains salts, fluoride, and chlorine. My roots absorb these minerals, but I have no way to expel them. They accumulate in my system, and my body sends them to the very tips of my leaves to concentrate them there, effectively sacrificing the tip to save the rest of the leaf. This results in the browning or "burning" you see. Over time, this salt buildup can also alter the pH of my soil, making it harder for me to absorb other essential nutrients.
My relationship with water is delicate. While I am drought-tolerant once established, my roots are also surprisingly susceptible to suffocation. If my soil remains constantly waterlogged, my roots cannot breathe. They begin to rot, and this damage underground prevents them from drawing up any water or nutrients at all. The first sign of this distress is often browning leaf tips, as the furthest points from the roots are the first to be cut off from supply. Conversely, if I am left completely parched for too long, the extreme dryness will also cause my leaf tips to desiccate and turn brown as a cry for help.
Please, you must understand that I am a unique being with specific dietary needs. Many common fertilizers, especially those that are high in phosphorus, are toxic to me. My roots are not equipped to process it. Applying such a fertilizer will cause rapid fertilizer burn, which manifests as browning leaf tips and margins. I thrive on a fertilizer that is formulated specifically for native plants like myself, one that is low in phosphorus or, ideally, has none at all.
I am built for sunshine and fresh air. If I am placed in an area with low humidity, especially indoors or in a sheltered spot, the delicate tips of my leaves can dry out from the air alone, even if my soil moisture is adequate. Furthermore, while I love the sun, a sudden extreme heatwave can sometimes overwhelm my systems, causing minor scorching on the most exposed parts of my foliage—the tips.
If I am living in a container, my world is limited to that pot. Over time, my roots can become pot-bound, circling tightly and filling every available space. This dense root mass makes it incredibly difficult for me to take up sufficient water and nutrients efficiently, especially as the soil depletes. The stress of this confinement will often show itself first on my leaf tips, as they are the most vulnerable parts of my structure.
