1	Hosta 101 Dr. Todd P. West Assistant Professor of Horticulture Division of Plant and Soil Sciences
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3	Introduction Natives of Japan, China, and Korea . Herbaceous perennial. Cold hardy in growing zones 3-10. 139 different species. 4000 cultivars. (about 500 are actually distinct and garden worthy). Divided into categories based primarily on leaf color: green, blue, gold, and variegated. They are also categorized by size: mammoth, large, medium, and small.
4	Hosta Sizes
5	Cultivation The are few perennials that are as easy to grow as hostas...if you remember a few rules: Like rich organic soils You can work in organic matter such as peat moss, manure or compost with the soil before planting. Prefer moisture A minimum of an inch of water each week is recommended. Water early in the day if needed. Plenty of light (without afternoon sun). Morning sun is always best, as the temperatures are generally cooler at this time. As hosta leaves are large, they transpire more moisture when grown in more light. This simply means that you will need to apply more moisture to accommodate the increasing transpiration rate.
6	"Ideally," Ideally, an organic fertilizer should be applied in early spring, then again in mid summer. Many gardens do not need additional fertilizer if a soil test shows the soil has sufficient amounts of the necessary nutrients. In this case, an addition of compost over the bed once a year, applied in the fall, is usually sufficient. While hostas will grow without such care, there is nothing quite like a well grown clump. Hostas are relatively unstable with respects to their genetics producing numerous ‘sports’. ‘Sport’: a plant or plant part that has undergone a genetic mutation.
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8	Soil Preparation Hostas will grow best in rich organic soil. A loamy soil type may not need the addition of organic matter, but few of us are so lucky to garden in ideal soil and will need to add organic amendments. The recommended soil is well drained, has a slightly acidic pH, and is enriched both with nutrients and organic matter. When making a new hosta bed, many gardeners like to cultivate to a depth of 12-16 inches. Apply 6 inches of organic matter and till it into the new bed. Materials such as compost, leaf mold, well-rotted manure, Canadian peat moss, composted pine bark, and municipal sludge products such as Milorganite and Com-Til® may be used. The addition of organic matter will also serve to raise the bed, which will improve drainage for the plants.
9	"The ideal pH range for..." The ideal pH range for hostas is 6.5-7.5. In higher pH soils, the addition of organic matter such as Canadian peat moss and cottonseed meal will tend to lower the pH. The planting hole should be dug at least a foot deep. The width of the hole should be one and a half times the expected mature size of the clump. Check the plant's label for ultimate size, or ask a nursery for information. Most hosta roots will grow and spread horizontally, so a large, wide hole is best.
10	Uses Landscape ornamental. In the garden or in a patio planter. Flower scape for floral arranging. Varying lengths of scapes. Flower colors are lavender and white. Some hostas produce a fragrant flower. Example: ‘Honeybells’ - a sun tolerant green hosta that produces loads of fragrant flowers mid-summer on five foot scapes. Leaves for floral arranging. Varying leaf textures, sizes, colors. Edible Used in stir-fry dishes in Asia.
11	Pests Worse than Telemarketers!
12	Deer Deer can eat all your hosta plants in one evening, leaving just the stalks standing. Ten-foot tall fencing and trained guard dogs are the only reliable method to keep them out of the garden. Gardeners also use deer repellant, a bitter-tasting chemical that is sprayed on the leaves. These products need to be re-applied after several rainfalls. Motion detector garden sprinklers have also been used with some success.
13	Slugs and Snails Slugs and snails are nocturnal foragers and are the most common pest of hostas. They eat small round holes in the leaves. By beginning an abatement program early in the spring, slugs may be easier to control. Slug signs: Look for silvery slime trails in garden beds to determine if slugs are present. They may be spotted during daylight hours or in the evening by using a flashlight. Since some plants are more susceptible to slug injury, check around those particular plants to detect slugs. Thin-leafed hostas and those with leaves growing close to the ground are most susceptible to slug injury.
14	Slug Controls
15	Barriers Copper strips. When a slug touches copper, it is charged with current, an unpleasant experience that makes it reverse course. Place a band of copper (preferably 3 inches wide) around beds or individual plants. Or form copper wire into a tight, conical spiral around each plant, with the small end at the bottom, and push the wire into the soil. Make sure slugs are not trapped inside barriers. Diatomaceous earth Made of ground mineral fossils, this powder punctures slugs' soft covering. Sprinkle it in a 1-inch-deep, 3-inch-wide band around a plant's base. Rain can destroy its effectiveness, so you may have to reapply it.
16	Traps Trap boards Slugs seek shelter during daylight. Place small, flat boards under plants and between garden rows. Remove slugs each morning and scrape them into a bucket of soapy water. Beer traps. Slugs are attracted to yeasty odors. To make a beer trap, cut a 2-inch hole about two-thirds up the side of an empty margarine tub or plastic yogurt container. Bury the container so the hole is just above ground. Add 2-3 inches of beer (or a mixture of 1 tablespoon (Tbl) yeast, 1 Tbl flour, 1 Tbl sugar, and 1 cup water) and cover with a lid. Remove dead slugs daily. Trap crops. Slugs love to eat marigolds. Plant marigolds along your garden's border and hand pick slugs and dispose of them in late evening.
17	Nontoxic Controls Iron phosphate granules (e.g., Sluggo, WorryFree, and Escar-Go). These granules have a wheat aroma to attract slugs. After eating them, slugs stop feeding, dry out, and die within 3 to 6 days. Bait remains active for about 1 week or longer depending on the environment.
18	Chemical Controls Ammonia-water spray When sprayed directly with a solution of equal parts household ammonia and water, slugs dehydrate. Test a plant's sensitivity to ammonia by spraying a small section and watching for a reaction in the next day or two. Metaldehyde Metaldehyde is the most common active ingredient in synthetic chemical baits. Use these baits in the fall. By late winter and early spring, conditions are too wet and slugs can recover. These baits are toxic to earthworms and may affect nontarget insects. However, it's possible to use them safely. Place a few pellets under a board and remove dead slugs each morning. Or, place granules in a 1-gallon plastic milk container. Make a 1-inch by 2-inch hole in the side of the container near the top and bury the container so the hole is above ground.
19	"Wood Ashes & Egg Shells" Wood Ashes & Egg Shells: Sprinkling the area surrounding your hostas with wood ashes or egg shells will deter slugs. The ash or egg shells irritate the slug's mucous membrane, damaging its skin. Newspaper trap Lay wet newspapers on the ground overnight. Check beneath these the next day to find slugs that have taken refuge from heat and sun. Kill the slugs by dropping them into a 10-20% solution of ammonia and water. Salt will also kill slugs if applied directly to them. Slug ring Use copper to make bands that go around the crown of the plant. Trap Crops Slugs love to eat marigolds. Plant marigolds along your garden's border and hand pick slugs and dispose of them in late evening.
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21	Slug Resistant Hostas Abiqua Blue Krinkles Big Daddy Blue Angel Blue Belle Blue Umbrellas Blue Wedgewood Bold Ruffles Christmas Tree Color Glory fluctuans Sagae fortunei Aureo-marginata Frances Williams Fringe Benefit Gold Edger Gold Regal Green Fountain Green Piecrust Green Sheen Hadspen Blue Krossa Regal Leather Sheen Love Pat Midas Touch Pizzazz Sea Lotus leaf Shade Fanfare Sieboldiana spp. and forms Snow Cap Spritzer Sum and Substance Tardiana types Tokudama spp. Zounds
22	Foliar Nematodes Microscopic-sized worms that can infest hosta leaves. Nematodes overwinter in the ground and move to the leaf where they feed between the veins. The symptom is a brown streak that appears between the veins in late July or August. Many folks don't realize that they have foliar nematodes, simply dismissing the early leaf browning to weather. Foliar nematodes are a new problem, and to date, current research has not found a way to eradicate them. There is no complete chemical control, and infected plants must be destroyed.
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24	"Detection:" Detection: Remove small pieces of the leaf tissue showing symptoms, place them in a clear glass dish and add sufficient water to submerge the tissues. After 24 hours, carefully examine the water with a 10X hand lens and a strong light. "You will see the nematodes as actively moving, glistening white threads," They can be detected by teasing apart leaf tissue with forceps while observing with a dissecting microscope. When receiving new hostas, you may want to wait to see if nematode signs appear prior to introducing the plant into your garden.
25	Rabbits, Squirrels and Voles, Oh My! Occasionally eat young shoots in the spring, and sometimes bite off flower scapes. Squirrels will eat hosta leaves during a drought, and sometimes dig up plants. Voles chew on the roots of hostas, and a heavy infestation of voles may kill plants. Wire cages made of hardware cloth encircling the hosta roots may deter them.
26	Viruses Viruses are another recent problem appearing on hostas. Hosta Virus X (HVX) – most important Symptoms include an irregular mottling of the foliage, yellow ringspots, or small yellow dots or flecks on the leaves. Spread primarily through: Mechanical means when tools, fingers or machinery such as mowing equipment become contaminated by contact with an infected plant and transmit the virus to susceptible healthy plants. Not transmitted by insect vectors or through seed or soil.
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28	Virus (Cont.) Prevention: Buy plants from supplier who tests and maintains virus-free stock. Recognition of the symptoms induced by HVX infection in susceptible cultivars. Avoiding mechanical transmission of virus. Adjusting planting distances between susceptible and tolerant cultivars. Elimination of infected plants. To diagnose this problem, leaf samples may be sent to: Dr. Ben Lockhart, Department of Plant Pathology, 495 Borlaug Hall, University of Minnesota, St. Paul, MN 55108-6030
29	Reaction of 57 Hosta cultivars
30	Humans Humans can be a problem if they like your hostas and decide that they need them more than you do.
31	Propagation
32	Hosta Sex Hostas do not come true when planted from seeds. H. ventricosa being the one exception. Just like people, hosta offspring will not look exactly like their parents. Sure, they will share a few of the same characteristics, but don't expect a series of great new hostas.
33	When I Grow Up, What Will I Look Like? The first rule of thumb is that the leaf color of the seedling will be derived from the color in the center of the leaf of the parent plant (grandparents are included here also). Green hostas will usually produce green offspring, Blue hostas will produce some blue, some green, and some gold offspring. Gold hostas will produce some of each also. Edged variegated hostas will NOT produce variegated offspring. Only hostas that have white streaks (streaky) in the center of the leaf will produce variegated offspring. White centered hostas will produce all white hostas which usually die in the seed pots due to a lack of chlorophyll.
34	Seed Propagation Seed pods can be gathered in the fall. They will not be killed by frost. Once you have taken the seeds from the pods, mix them with a little dampened peat moss and put them in a plastic bag in the refrigerator for three months. After 3 months plant them in flats and cover the seeds with about 1/8 to 1/4 inches of soil. They germinate at about 70 degrees in a couple of weeks. Once the plants are set out it seems to take about five years for them to reach their growth height and width.
35	Division Propagation of hostas is easily achieved by dividing existing plants. Most home gardeners will propagate hostas by division. Division should be done when no shoots are growing from the center of the mature clump and this bare area detracts from the appearance of the plant. Division of the clump will improve the plant's appearance. Lift the entire hosta clump and wash the soil from the roots, if possible, to make it easier to see where to cut to divide the clump. Cut with a sharp knife to make the divisions.
36	"Spring is the easiest time..." Spring is the easiest time to divide plants because new shoots are only a few inches high and the leaves have not expanded. Do not divide the sieboldianas or the Tokudamas in spring. Be careful not to overdivide hostas in spring; divide only the fast growing hostas then. New roots will not grow until the foliage has fully expanded and hardened off. During this period, the leaves may desiccate quickly on warm days, since the roots have been reduced in size or were injured during division. A hot day may cause injury such as leaf burn, but this is probably not permanent damage. Though spring division is easiest, summer division is preferred. Can be done in August, at least 30 days before the first fall frost date. Warm soil and higher humidity at this time promotes better root growth, and plants may put on a little growth spurt at this time.
37	"Keep newly divided plants well..." Keep newly divided plants well watered for the first two weeks, especially if there is a period of drought. Some of the larger leaves on a division may be cut back to reduce water loss. Frequent division of a clump will restrict plant and leaf size, and keep it from developing to its desirable mature features.
38	Hosta Production Rates Crown Division vs. Micropropagation
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41	Plant Selection With so many hostas available, it can be difficult to determine which plant(s) you want for the garden. Each variety of Hosta may have a slightly different light requirement, so you can plant them in almost any light situation. Blues prefer more shade, Golds will tolerate sun better. To help you get started, here is the American Hosta Society Popularity Poll from 2000. Each year the Society polls its members for their favorite hostas, then develops this "Top 20" list.
42	Companion Plants Companion plants enhance the appearance of a planting of hostas. Early blooming bulbs and perennials are especially nice with emerging hosta leaves. Spring bulb foliage can be hidden after blooming by the larger hosta leaves. In summer months, bright annuals such as impatiens, begonia, and coleus make attractive companion plants. Numerous shade plants are available that enhance hostas: Brunnera, Disporum, Heuchera, Pulmonaria, Thalictrum, Tiarella, ferns. Transition plants (from sun to shade) Hakonechloa (ornamental grass)
43	Top Nine Hosta Myths (Tony Advent Plant Delights Nursery) Myth 1: If you fertilize hostas they will turn green. Reality: We see many consumers that still believe this. Obviously, this was perpetuated when H. 'Undulata' was the prevalent hosta sold and nurseries didn't understand the process of viridescence. Hostas are actually very heavy feeders. Myth 2: Hostas are very drought tolerant. Reality: Hostas hate dry soils. While they might last though one drought, a continuing drought will result in an irreversible decline and often a dry rot or disintegration of the crown. A hosta that continues to grow well in what seems like dry soil has actually sent roots deep enough to find extra moisture. Myth 3: Hostas need to be regularly divided like daylilies Reality: This myth is probably perpetuated by neighbors who simply want divisions for themselves
44	"Myth 4:" Myth 4: You can get rid of foliar nematodes by picking off the leaves that show damage. Reality: I've had several nurserymen try to pass this one off as true. I guess you can convince yourself of anything if you want to believe it bad enough. The fact is that plants can be filled with nematodes and show no visible symptoms. The plants will still spread nematodes to other nearby plants...usually within 3 feet. The display of symptoms is cultivar specific. The only way to be sure that a particular plant is clean is with a nematode test. Myth 5: Hostas can only be divided in spring. Reality: In fact, many commercial growers perform most of their dividing chores in the summer. Myth 6: Hostas prefer shade. Reality: While a few wild hosta species actually grow in shade, the majority prefer some sun. In the wild, most hosta grow either on rock cliffs or in sunny meadows...often with daylilies.
45	"Myth 7:" Myth 7: When I have a mutation on a hosta, I should give it a name and introduce it. Reality: Ideally, hostas should only be named and introduced if they are an improvement. A green reversion of a variegated hosta is almost never an improvement. Such introductions serve only to confuse the public and dilute the hosta trade with junk. Myth 8: Tissue culture hostas are inherently bad. Reality: Nothing could be further from the truth. Without tissue culture, we would only have a fraction of the cultivars that are available today. Tissue culture is one of the best methods for cleaning up a hosta with foliar nematodes. Just like with garden divisions, all reverted shoots must be removed and discarded. Obviously there are going to be more reversions in tissue culture, so attention to detail is critical. The bad reputation of tissue culture is due to labs that had poor quality control procedures.
46	"Myth 9:" Myth 9: I like hostas, so I should start a hosta nursery and make lots of money. Reality - This one sounds really good in theory, but if an accountant took a look at the books of most small hosta nurseries, they would recommend that you instead consider a passbook savings account or an extra job flipping burgers. The profit margins that seem huge to the public simply don't exist...especially now that the days of $200 hosta introductions are long gone. If a hosta is grown to a quality size, it will be one of the least profitable perennial crops that you can grow.
47	Organizations The American Hosta Society http://www.hosta.org/ The American Hosta Society is a society of people, whose focus is centered on the "friendship plant". We are organized for educational and scientific purposes, and especially to promote, encourage, and foster the development, improvement, and enjoyment of the genus Hosta.
48	Online Resources http://www.hostalibrary.org/ Photo library of all registered Hosta varieties
49	Book Recommendations The Hosta Handbook by Mark R. Zilis (Q & Z Nursery Press) The new bible on hostas. The Hosta Book by Paul Aden (Timber Press) Quite dated (considered to be the old bible) but a good introductory book for those just beginning in the hosta world . The Gardeners Guide to Growing Hostas by Diana Grenfell (UK via Timber Press) The best on the market today for the average gardener/collector The Genus Hosta by George Schmid (Timber Press)- Unparalled life work on every facet of the genus hosta. This is a valuable reference book, but it can be overwhelming. Gardeners with less than 100 different hostas...wait on this one. The Journal of the American Hosta Society A truly fabulous 2/yr publication of the society featuring color pictures and informative article. This is without a doubt the best publication of any plant society, and a must for anyone interested in hostas
50	Vendors http://www.plantdelights.com Raleigh, N.C. http://www.directsourcehostas.com Glenview, IL Free Hosta Offer (Shipping Cost of $8.00) http://www.hostahosta.com/ Chapel Hill, NC http://www.directsourcehostas.com/ Photo library linked to www.hostalibrary.org http://www.singletree.com Shopping by Leaf Color and Special Features