The slow-growing ‘Halcyon’ cultivar is one of the best and most popular in its group. It is an erect plant growing to about 14 inches tall with heavily textured. spear-shaped blue-green leaves. The texture of the leaves resembles that of seersucker fabric. Unlike some other plants with blueish-green foliage, this one retains its color well without fading in the heat of summer. ‘Halcyon’ sends up pale lilac-blue flowers on 26-inch stalks in mid- to late-summer. Hummingbirds and bees are attracted to its blooms. If planted in partial sun, ‘Halcyon’ will need extra water. Unlike some of the yellow-leaved hostas, ‘Halcyon’ cannot tolerate more than a few hours of direct sunlight each day. If planted under trees, they require more water to compensate for the moisture absorbed by tree roots. Hostas usually do not require division unless you want to propagate more plants. When the foliage dies back in the fall, remove the spent foliage to keep the garden clean for the following spring and to remove hiding places for slugs and small rodents.
Light
Hostas as a group prefer to be planted in partial shade to full shade. The ‘Halcyon’ cultivar grows best in shadier conditions because their bluish-green foliage can appear somewhat washed out if it receives too much direct sunlight
Soil
All hostas prefer relatively cool, moist but well-drained soil. They do best in neutral soil (soil pH 7.0) but will tolerate slightly acidic soil (pH about 6.5).
Water
Hostas prefer consistent moisture but will tolerate somewhat dry soil better than constantly wet soil.
Temperature and Humidity
Hostas do quite well in the climates in their hardiness zone. They might wilt in very warm temperatures unless frequently watered, and high humidity sometimes encourages snails and slugs. Hostas are sensitive to cold and will succumb at the first frost. They do not emerge in the spring until the soil has warmed considerably. Hostas require a moderate amount of winter chilling (temperatures below 40 degrees Fahrenheit for a few weeks) to thrive and thus are not suitable for very warm climates.
Fertilizer
Hostas generally don’t require much, if any, feeding, especially if they are growing in good, rich soil. Hostas that are planted in dry, poor soils will benefit from diluted liquid fertilizer applied over the plants every four to six weeks.
Pruning
Because hosta flowers are not very showy, many gardeners remove the flower stalks. But hosta blooms are very attractive to bees, hummingbirds, and other pollinators, so environmentally-minded gardeners are increasingly leaving the flowers in place until they have faded completely, at which time the dried stalks can be cut down to their base.
Propagating ‘Halcyon’ Hostas
Hostas are easily propagated by digging up and dividing the root clumps into halves or quarters. This is best done in early spring or late summer, but most hostas will survive division at almost any time. Because ‘Halcyon’ is slow-growing, it’s best to limit division for when you truly want to propagate the plant because division is not necessary for the health of the plant. Hosta roots are very tough, and division can be difficult, especially if the soil is very wet. The best method is to use a sharpened spade to first slice down through the middle of the plant before digging it up in pieces.
How to Grow ‘Halcyon’ Hostas from Seed
Though it is possible to grow ‘Halcyon’ hostas from seed, the germination rate is extremely low and the success rate for seedlings is very poor. Therefore, most choose to propagate hostas through division, which is the much more reliable method.
Potting and Repotting Halcyon Hostas
Many hostas can be planted in containers, and ‘Halcyon’ is no exception. Make sure the pot has good drainage, use good-quality potting soil, and place the container in dappled or indirect sunlight. Choose a decorative plastic or terracotta pot, and make sure the depth of the pot is less than the width; all hostas love to spread out their roots, and a shallow but wide planting vessel will help them achieve that.
Overwintering
Protect container-grown hostas to ensure they survive the winter by sheltering them in a south-facing location against the house or in an unheated garage. Hostas grown in the ground can be left where they are, covered with mulch to help protect them during extremely cold temperatures. Remove the mulch when temperatures warm up in the spring..
Common Pests
Few serious pest and disease problems affect hostas, but those that do occur can be something of a plague: snails and slugs will often chew ragged holes in the foliage. This is disfiguring and unattractive, but it rarely kills a plant. These pests can be baited to collect them for removal. Keeping the ground free of thick mulches can also discourage slugs and snails. Hosta is not deer resistant, and the foliage is quite a favorite meal for them.