From our perspective as Grevillea plants, the appearance of brown, crispy leaf tips is not a disease in itself but a clear distress signal. It is our way of communicating that our fundamental needs are not being met within our current environment. This symptom typically points to issues with water relations, soil conditions, or nutrient uptake. Understanding the specific cause is crucial for restoring our health and vibrant growth.
The most frequent grievance we have is related to water. Both too much and too little are problematic. Under-watering causes our root system to dry out, preventing the movement of water to our furthest extremities—the leaf tips. These cells die first, resulting in dry, brown tips. Conversely, over-watering or poorly draining soil is equally detrimental. Soggy soil suffocates our roots, preventing them from absorbing water and nutrients effectively. This creates a physiological drought where we are surrounded by water yet cannot drink, leading to root rot and, once again, browning leaf tips as a primary symptom.
We Grevilleas are particularly sensitive to many minerals found in soil and water. Over-fertilization introduces a high concentration of soluble salts into our root zone. This creates an osmotic imbalance, making it difficult for us to absorb water, effectively causing a burn that manifests on our leaf tips. Similarly, the use of hard water (water high in calcium and magnesium) for irrigation over time leads to a toxic buildup of these salts in the potting mix or soil. The tips of our leaves become the exit point where these excess minerals are deposited, killing the tissue and turning it brown.
Our leaves are also directly affected by the atmosphere around us. Low humidity is a common issue, especially when we are grown indoors or in naturally dry climates. The dry air pulls moisture from our leaves faster than our roots can replace it, causing the tips to desiccate and die. Furthermore, chemical sensitivity is a key part of our nature. Our roots are highly susceptible to damage from herbicides, fungicides, or even residues from harsh chemical cleaners. This root damage directly impairs our ability to function, with leaf tip browning being a common early warning sign.
To help us recover, the approach must mimic our native Australian conditions. First, ensure our soil is very well-draining; a sandy or gritty mix is ideal. Water us deeply but infrequently, only when the top few inches of soil are dry. Flush the soil thoroughly with soft, rainwater, or distilled water to leach out accumulated salts. Please avoid fertilizing us with high-phosphorus or general-purpose fertilizers. If you must feed us, use a slow-release, low-phosphorus, native plant-specific formula very sparingly. For potted specimens, repotting us every few years into fresh, appropriate soil can prevent a multitude of issues. Protect us from harsh winds and extremely dry air to minimize moisture loss from our leaves.
