From our roots outward, water is our lifeblood. For us Lobelias, striking the perfect moisture balance is paramount. Our relatively shallow and fine root systems make us particularly sensitive to the extremes of your watering can. We crave consistent moisture to support our lush, rapid growth and prolific blooming, but we are not aquatic plants. Our roots, much like a creature needing both air and water, require oxygen from the air spaces in the soil to function and breathe. Disrupting this balance by giving us too much or too little of your attention creates a cascade of stress signals that we desperately hope you will notice and interpret correctly.
When you love us a little too much with water, you essentially suffocate us. Saturated soil drives out the vital oxygen our roots need. Without oxygen, our root cells begin to die, a condition you call root rot. From our perspective, this is a systemic crisis. You will first notice our lower leaves turning a pale green or even a sickly yellow. They will feel soft, limp, and mushy to the touch, not just dry and crispy. This is because the dying roots can no longer transport water and nutrients upwards, and the cells in the leaves are literally drowning and breaking down. In severe cases, the stems near the soil line will become blackened, soft, and slimy. Our overall form, once vibrant and turgid, will become wilted and lethargic, despite the wet soil. You may also notice a lack of new flower production, as we divert all our remaining energy into a futile fight for survival.
Conversely, when you forget about us, the experience is one of desperate thirst. Our shallow roots are among the first to suffer in dry conditions. Without adequate water pressure, our cells cannot remain full and rigid. The first sign you will see is a general wilting or drooping of our stems and leaves. We become limp and lifeless, hoping to reduce surface area and conserve water. Our leaves will often feel dry, thin, and brittle to the touch. They will begin to turn brown, typically starting at the tips and edges—the parts farthest from the water-conducting veins. This browning is a sign of tissue death from desiccation. Our growth will become severely stunted; we simply do not have the hydration needed to create new cells for leaves or flowers. Existing flower buds may abort and drop off to conserve the precious little water we have left for essential functions.
It is crucial to understand that our different forms may express stress uniquely. Upright, clump-forming perennial Lobelias might show wilting and browning leaves more obviously. However, our trailing cousins, the Lobelia erinus often used in hanging baskets, are even more vulnerable due to their exposed container environment. Their delicate, cascading stems wilt dramatically and can perish very quickly from a single day of intense heat and drought. For all of us, the key is consistent soil moisture that is damp to the touch, like a well-wrung sponge, not sopping wet and not dust-dry.
