To understand our watering needs, you must first understand where we come from. Most Grevillea species are native to Australia, thriving in well-drained, often sandy or rocky soils. Our root systems are adapted to seek moisture deeply but are also highly susceptible to sitting in consistently wet, heavy soil. This environment has trained us to prefer a cycle of thorough watering followed by a period where the soil is allowed to dry out significantly. When brought indoors, our fundamental need for excellent drainage and oxygen around our roots does not change. Overly generous and frequent watering is the single greatest threat to our health indoors, as it suffocates our roots and leads to fatal root rot.
You cannot water us on a fixed schedule (e.g., "every Tuesday"). The rate at which we use water is influenced by factors like season, indoor temperature, light levels, and pot size. The only reliable method is to physically check the soil moisture. Insert your finger into the soil up to the second knuckle (about 2 inches deep). This is crucial because the surface soil can feel dry while the root zone below is still moist. Water us only when the soil at that depth feels dry. If it feels cool or damp, delay watering and check again in a few days. This simple test aligns your care with our actual needs, preventing both drought stress and the far more dangerous overwatering.
Our thirst changes with the seasons, mirroring our natural growth cycles. During the spring and summer, we are in our active growth phase. Increased daylight and warmer temperatures prompt us to grow and photosynthesize more, meaning we will draw water from the soil more rapidly. You will likely find that the "finger test" indicates a need for water more frequently, perhaps once a week or so, depending on conditions. Conversely, in the autumn and winter, our growth slows dramatically or enters a dormant period. With lower light levels and cooler temperatures, our water consumption plummets. The soil will take much longer to dry out. During this time, you may only need to water us every two to three weeks, or even less. Always let the soil condition, not the calendar, be your guide.
How you water is as important as how often. When the soil is dry to the touch at a 2-inch depth, provide a thorough, deep watering. Slowly pour water onto the soil surface until you see it begin to flow freely out of the drainage holes at the bottom of the pot. This ensures the entire root ball is evenly moistened. It is imperative that our pot has one or more drainage holes. Never let us sit in a saucer full of drained water for more than 30 minutes; always empty the saucer after watering. This practice flushes out salts and guarantees that excess water escapes, creating the well-drained, oxygen-rich environment our roots require to avoid rot and stay healthy.
