Appearance: Leaves can range from tiny ("Blue Mouse Ears") to massive ("Blue Angel"), often featuring deep ridges or puckered textures.
Flowers: Most varieties produce tall stalks of bell-shaped flowers in shades of lavender, white, or pale blue during the summer.
Seasonal Color: The blue is most intense in spring. In high heat or heavy rain, the wax can "melt" or wash away, causing the plant to transition to a standard green for the remainder of the season. 
Light: Blue hostas require more shade than other varieties to preserve their color. Deep shade or dappled morning sun is ideal; avoid harsh afternoon sun, which will bleach the blue coating.
Watering: Keep the soil consistently moist but well-drained. Crucial: Apply water directly to the soil. Overhead watering can damage the waxy blue coating or cause it to appear spotty.
Soil: They thrive in rich, organic soil that is slightly acidic (pH 6.0–7.0). Amending the soil with compost or aged manure is highly beneficial.
Maintenance:
Pruning: Remove spent flower stalks after blooming to focus the plant's energy on its foliage.
Pests: Slugs and snails are the primary threat. Use slug baits or diatomaceous earth to protect the leaves.
Winter: Cut back foliage to the ground after the first hard frost to prevent overwintering pests. 
Popular Blue Cultivars
Blue Angel: One of the largest varieties, forming massive mounds up to 4 feet wide.
Halcyon: Known for its intense blue color that lasts longer into the summer than many other types.
Blue Mouse Ears: A charming miniature variety with thick, round leaves.