Hostas are one of the most popular perennials for home gardeners, offering ease of care for beginners, and an endless variety of color patterns, shapes, textures and sizes for the avid collector. Native to northeast Asia, hostas were brought to North America in the 19th century by horticulturists and plant collectors. Thanks to the development of tissue culture and decades-long adoration, there are now more than 8,000 hosta cultivars.
Provided a few guidelines are followed, hostas are long-lived powerhouses for the shade garden. Although they are adaptable and forgiving once established, they perform best with consistent moisture in well-drained, slightly acidic soil. They need about 1 inch of water per week, either from rain or irrigation, and 2 inches of a good organic mulch will help to retain that moisture. Hostas will have the best color development with some light, so do not plant them in deep shade. Morning sun with afternoon shade or high dappled shade is best.
Do not provide supplemental water once they go dormant for the winter, or before the last frost date in spring, as this could lead to root rot. Fertilize in early spring once the leaves have emerged. Fertilizer is particularly helpful for optimal growth of gold-leaved varieties as they do not have as many chloroplasts (the part of plant cells responsible for photosynthesis). Hostas benefit from dividing every few years, and center-clump dieback is a sign your plant is overdue for division. Fall is the optimal time to make divisions, although it can be done successfully at other times of the year as well.
Gardeners are not the only ones who love hostas. They are eaten by deer, rabbits, voles and slugs, but actions can be taken to help minimize casualties. Slugs like damp and decaying debris, so cleaning up and removing dead leaves, as well as not overwatering will help reduce these slimy pests. If possible, water with drip hoses instead by overhead irrigation. If this is not possible, water in the early morning so the area is not wet overnight. If slug damage still occurs, natural controls such as diatomaceous earth, or baits with iron phosphate can be used. Thinning surrounding plants to increase air circulation can also help.
The likelihood of deer and rabbit damage can be reduced with repellents, which are available at most home and garden stores. Be sure to reapply these after a heavy rain, and use gloves during application so that smell doesn’t linger on your hands.
Barriers such as fencing, netting and motion-activated sprinklers can also be effective. Vole damage is trickier since they feed underground, and often their activity is not discovered until the plant is already dead. Hostas can be planted in wire cages to prevent vole damage while still allowing for proper drainage. Surrounding the root ball with sharp gravel can also help. Above ground, hostas grow very well in containers for those with vole issues, limited space or as a design element.
While hostas can certainly be stars of the shade garden solo, they are even more stunning with companions that thrive in similar growing conditions. Dear friends include columbines, hellebores, sedges, coral bells and lungworts. Bonus points are given for striking color combinations such as purple Iris cristata paired with a variegated hosta such as Tambourine or Valentine bleeding hearts intermingled with the blue-leafed Hosta sieboldiana Elegans.
Many hostas even provide fragrant flowers such as hosta So Sweet.
Happy gardening.
Michelle Baudanza is the curator of herbaceous plants at Norfolk Botanical Garden.
