From our perspective, water is the essential lifeblood that transports nutrients from the soil, through our roots, and up to every single leaf. We hostas are primarily composed of water, and our large, broad leaves have a significant surface area from which moisture can evaporate. This makes us inherently thirsty plants. Without consistent and adequate hydration, our systems go into distress. Our roots, which form a dense, fibrous mat, are designed to efficiently absorb this moisture, but they cannot seek out water on their own. They rely on you to provide it at the soil level where we live.
Our most fundamental need is for soil that is consistently moist, but never waterlogged. This is the single most important concept for our health. "Consistently moist" means the soil around our roots feels like a well-wrung-out sponge—cool and damp to the touch. When this balance is achieved, our roots can breathe and absorb nutrients efficiently. "Waterlogged" or soggy soil is a death sentence for us; it fills the air pockets in the soil and suffocates our roots, leading to rot. This is why the quality of your soil, specifically its ability to drain while retaining moisture, is just as crucial as the watering itself.
The frequency of watering is not set to a simple weekly schedule. It is a direct response to your local environment. You must check the soil! The best method is to insert your finger into the soil near our base, about 2-3 inches deep. If the soil at that depth feels dry, it is time to water. During the peak heat of summer, especially if we are planted in sunnier spots, you may need to water us every 2-3 days. In the cooler, shadier conditions of spring or fall, or if rainfall is consistent, we may only need a deep drink once a week. Newly planted hostas require more frequent attention until our root systems are fully established.
When you do water, please do it thoroughly. A light sprinkling that only dampens the surface is worse than not watering at all. It encourages our roots to grow shallowly, making us more vulnerable to heat and drought. Instead, we need a deep, slow soak. Apply water directly to the soil at our base, avoiding our leaves to help prevent fungal diseases. Continue until the water has penetrated at least 6-8 inches into the ground. This encourages our root systems to grow deep and strong, which in turn makes us more resilient and better at accessing water reserves in the soil between waterings.
Several factors will change our watering needs. Hostas planted under large trees are in a double-edged situation; while the tree provides shade, its extensive roots are fierce competitors for every drop of water and nutrient in the soil. We will need more frequent watering in these locations. The type of soil is also critical. Sandy soil drains too quickly and will require more frequent watering. Heavy clay soil holds water for a long time, so you must be cautious not to overwater. Applying a 2-3 inch layer of organic mulch around our base (but not touching our crowns) is immensely helpful. It regulates soil temperature, suppresses our weed competitors, and most importantly, drastically reduces moisture evaporation from the soil.
