From our perspective beneath the soil, overwatering is a silent emergency. Our roots require oxygen to respire and function. When you apply water too frequently, the air pockets in the soil are flooded, creating an anaerobic environment. We essentially begin to drown. This suffocation causes our root cells to die, turning them from firm and white to soft, brown, and mushy. This condition, root rot, is a death sentence if unchecked. With our root system compromised, we cannot uptake the water and nutrients you are providing, ironically creating symptoms similar to thirst in our upper parts while our foundations decay.
Our leaves are the most visible communicators of our distress. When our roots are failing due to overwatering, the first signal we send is a generalized yellowing of the older leaves, known as chlorosis. This happens because the damaged roots cannot supply essential nutrients. You may also see us wilt, not from lack of water, but because the rotting roots can no longer transport it. The leaves will become soft, limp, and may eventually drop. In severe cases, you might observe blisters or lesions on the leaves (oedema) as our cells rupture from taking in more water than we can transpire.
Conversely, when you underwater us, our existence becomes a desperate search for hydration. Our root tips, which are responsible for water absorption, will desiccate and die back in dry soil. We will attempt to grow deeper and wider in search of any residual moisture, but if the entire root ball becomes too dry, we cannot recover. The soil will shrink away from the edges of the pot, and water may run straight through without being absorbed. We are not being difficult; we are simply parched to our core, and our vital structures are dying from a lack of the most fundamental resource.
Our leaves will show you unmistakable signs of thirst. To conserve the little water we have, we will close our stomata and reduce transpiration. This causes our leaves to become limp and lose their turgor pressure, making us wilt. However, unlike the soft wilting of overwatering, the wilting from thirst is often followed by a dramatic change in texture. Our leaves will become dry, brittle, and crispy to the touch, particularly at the edges and tips. We will often curl our leaves inward or fold them along the midrib to reduce surface area and minimize water loss. We may also drop leaves prematurely to conserve resources for our most essential functions.
Whether you give us too much or too little, the ultimate sign of our distress is a halt in growth and flowering. As a Grevillea, our goal is to flourish and produce vibrant, spider-like blooms. Both extremes of water management cause immense stress, diverting all our energy from growth and reproduction into basic survival. You will notice a lack of new shoots, and any existing buds may abort or fail to open. We become stunted and unable to express our natural, beautiful form. Correct water management is the key to seeing us thrive as we are meant to.
