Hostas (Hosta spp.) are herbaceous perennials prized for their showy foliage and ease of care. Many thrive even in shady conditions. Hostas are not shrubs, which sprout from woody stems. Instead, hostas sprout from underground, thick horizontal roots called rhizomes, which are similar to bulbs. Unlike shrubs, herbaceous perennials usually die back to the ground but then grow again the next season.
Perennials and shrubs have several things in common. Both grow and bloom year after year if conditions are right. The primary difference is that shrubs (and trees) are woody, which means their vascular systems are surrounded by heartwood and bark. In addition, although deciduous shrubs drop their leaves, the woody stems remain and do not die back to the ground each year. Evergreen shrubs even keep their leaves.
Herbaceous perennials, on the other hand, do not have wood. They sprout on tubers, rhizomes or bulbs -- all of which are found underground. As a perennial dies down to the ground each year, it returns its nutrients to the tuber, rhizome or bulb from which it grew. There, the nutrients are stored until the plant is ready to sprout and grow again the next year.
Hostas will not act like perennials -- that is to say, they will not grow again the next season -- if they are not grown in the proper climate. Hostas like cold winters and cool summers. They grow best in U.S. Department of Agriculture plant hardiness zones 3 through 8. Hostas require a cooling period during which they can go dormant and conserve their resources. Winters in USDA zones warmer than 8 will be too warm for the plants, and they will not be able to enter a dormant state. The result is that they will act as annuals -- they will live and bloom for one season only.
Hostas are some of the lowest maintenance perennials on the market. Several thrive even in the shade cast by evergreen trees, while others enjoy exposure to partial sunlight. Most grow best locations that have morning sun followed by afternoon shade, according to Ohio State University. In general, hostas that have bluish-green leaves can tolerate more shade than those that have golden or white leaves. Too much sun will burn the edges of the leaves, turning them brown and dry, and may also fade the colors of the leaves. Hostas grow best in moist but well-draining soil. Standing water may cause the rhizomes to rot, but on the other hand, they will not grow well at all in dry conditions. A minimum of an inch or so of water per week is ideal for these plants.
- Photo Credit Jupiterimages/liquidlibrary/Getty Images