The Perfect Perennial for Good Reason
Designating any one plant the "perfect" perennial invariably provokes a lively debate among gardeners. However for gardening in the shade, one plant stands head and shoulders above the rest. Hostas are shade-tolerant, low maintenance, quite forgiving, incredibly elegant and, quite possibly, habit-forming. And they are currently the most popular perennial in the U.S.
Plenty Hardy for the Midwest
Hostas are hardy, herbaceous perennials meaning they emerge each spring from winter dormancy. Unlike many perennials, they are primarily grown for their foliage. Native to China, Japan and Korea, hostas were introduced into the U.S. (via Europe) in the early 1800's. Today there are literally thousands of different hosta cultivars available reflecting their overwhelming popularity with home gardeners.
An Incredible Range of Foliage Options
The range of hosta foliage color, shape, texture and size is extraordinary. Foliage colors include green, blue, white, gold and countless unique variegated combinations. Leaf shapes include circular, oval, heart and lance in both upright and symmetrical mounding habits. Leaf texture can be smooth, glossy, cupped, seer-suckered or rippled. Mature plant size ranges anywhere from 2" in height and 4" in width up to 36" in height and 60" (or more) in width. And if this range of options weren't sufficient, hosta also bloom in colors ranging from white to lavender to purple. Some varieties are even fragrant.
With this range of choices you will find a hosta for almost every landscape situation and effect- from containers to edging to groundcover to background planting and specimen planting. Hostas are quite effective among other companion shade perennials and shrubs including astilbe, dicentra (bleeding heart), ferns, tiarella (foam flower), tradescantia (spiderwort) and hydrangea.
Shade Loving vs Shade Tolerant
Hosta are shade tolerant and not shade loving as many of us had thought. The irony about hostas is that they actually grow and bloom more vigorously in full sun. However the leaves also become scorched and unattractive. While some varieties are touted to be more sun tolerant, I hesitate to recommend their use in full sun due to our Midwest summer sun intensity, hot temperatures and drying winds. Nonetheless most hostas will benefit from a couple of hours of morning sun.
When placed in sites with more sun exposure, additional water will be needed to help avoid leaf scorch. While trees provide essential shade, they also compete with hostas for moisture and nutrients. Once established, hosta can tolerate a drier shade although they will always be more vigorous with consistent moisture.
Very Few Pests to Worry About
Hostas are relatively pest-free. Slugs are the most common pest which work at night leaving small holes in the leaves. Slugs require moist and dark conditions and prefer soft, immature leaf growth. Mature leaves and those with more substance (i.e. thicker leaves) are generally more slug-resistant. Good horticultural practices can also reduce slug damage. Mulching with a rather coarse bark mulch (but leaving the ground bare about 6" around the base of the plant) and generous spacing between plants permits good air circulation and creates a dry and rough surface that the slugs would rather not travel over. Avoid watering late in the day so that the foliage is dry at night. If all else fails, commercial slug baits are available. Make sure to follow label directions and reapply as directed. Rabbits and deer can present problems. While commercial repellant sprays are available, I have found a physical barrier (netting, fencing, etc) to be the only effective way to combat these larger pests.
Hostas are generally purchased as potted plants which means they can be planted any time during the growing season including summer and fall as long as adequate moisture is provided. Work organic matter (I prefer spaghnum peat) into the soil at the time of planting. Hosta prefer well-drained soil that is slightly acidic, but thrive even in our alkaline clay soil. If the hosta is root-bound in the container, tease the roots loose before planting. Use a root stimulator solution at the time of planting to encourage root growth, then mulch to a depth of 1" to 1-1/2". Keep the soil evenly moist for at least a couple of months or until the plant is established.
The Great Divide ???
Each year your hosta will reward you with additional offsets that enlarge the clump size. Hostas take 3 to 6 years for the foliage to develop a mature texture and character. Unlike many perennials, hosta do not need to be divided unless you feel compelled to propagate additional plants. Hosta can be divided any time from spring until early fall as long as the roots have time to develop before the first frost. Division is easiest in the spring shortly after the "eyes" emerge from the ground, although many consider fall the optimum time for division. Use a spade to remove a wedge-shaped portion from the clump or dig the entire plant and section it into as many divisions as desired.
Fall and Winter Care
Hosta are quite hardy in Kansas City and over-wintering is easy. I prefer to leave the dead foliage in place along with fallen tree leaves to provide additional insulation for the winter. Leaving the old flower stalks (or bloom scapes) in place helps mark the plant's location to avoid trampling new growth the following spring.
Buyer Beware !!!
One final word of caution: Many "casual" hosta users thought they could stop whenever they wanted. What begins as an innocent interest can quickly develop into a full-blown addiction. If you routinely tell your spouse you paid less than you really did for a new hosta introduction, or brag about how many hosta cultivars you have growing in your garden, you may need help. At Made in the Shade Gardens you can meet other hostaholics that share the same "affliction".