General Hosta Growing Information
Selecting a Location
Hostas are some of the best plants for shade. They add lush foliage to shady areas in northern climates, almost as if the garden was a tropical paradise. Still, many hosta plants do tolerate the sun, especially hostas with fragrant flowers. When planting them in the sun they will need a lot moisture, and if your plants do get sunburn then move them to more shade.
Spread out the roots so that they are not coiled in the bottom of the hole. Sometimes forming a cone of soil in the bottom will make it easier to place your hosta in the hole and spread out the roots over the cone. Plant so that the crown and roots are completely covered and the tips of dormant eyes are completely below the surface (see guide below). When planting hostas that are already leafed out you should keep them at the same level they were previously growing. If the stems are planted too deep then the outer leaves will usually rot and die off however new leaves should grow back to take their place if that ever happens, as the plant adjusts to the new depth.
Keep your hostas moist but not too wet. They don't mind having their roots in water, but the crown should stay relatively dry and its best to let the soil dry slightly between watering. Early season flooding will not hurt hostas as long as the water recedes later. In the wild hostas receive about 1" of rain per week and it is best to give a good deep watering once or twice a week rather than light watering more often to encourage deep, strong roots. If your hostas do not get enough moisture then they can eventually suffer dry rot. When this happens the roots dry out and rot off from the crown. The crown will actually shrink over the course of the growing season. Unfortunately because much moisture is stored in the leaves the effects of dry rot will not always be apparent until the following season. If your hostas suffer through a drought and then come back smaller the following year then they have most likely suffered dry rot.
When mulching your hostas, don't allow the mulch to cover the crown or touch the leaf stems as this can cause rot. Form a ring of mulch around the base, just covering the roots, without getting close to the crown. Hostas are heavy feeders so keep fertilizer away from the crowns. Feed sparingly but feed often. If you use water soluble fertilizers, mix it very diluted and only fertilize after the plants have been watered to avoid damaging them. Established hostas enjoy a high nitrogen feeding early in the season, but require balanced feeding as the season progresses. Too much nitrogen can cause leaves to be thin and weak making them susceptible to damage from slugs, wind, or rain. Stop feeding hostas in late August or early September so you don't encourage new growth near the first freeze. In the fall, allow your hosta leaves to experience a hard freeze so that the foliage dies back naturally. After the foliage has completely died back then it will easily pull away from the crown with a rake or with your hands. Discard or burn the old foliage to reduce the risk of overwintering foliar nematodes.
Hostas can be divided from the time they poke out the ground up until September. Divisions made during the heat of the summer will need more moisture to get them established, but they will bounce back quickly. Avoid dividing plants too late in the year. Crowns that are cut need time to heal before winter. Plants that have been cut in the fall may not heal until the following spring, allowing a greater chance of crown rot from bacteria or fungus during the winter. Fall division and transplanting will be much more successful if you don't damage or cut the crowns in the process.
Slugs and Snails
A major enemy of the hostas are slugs and snails. To prevent damage, sprinkle slug bait around the base of your hostas or place a saucer of beer in the garden to trap them. Pick them off when possible, and keep the garden free of excess debris so they don't have too many hiding places. Use slug bait sparingly as it may be toxic to dogs and other animals, and if you use too much in any one spot you may attract more slugs to the garden. The best time to spread slug bait is in the fall during an Indian summer (above average temps following the first frost). By killing the slugs in the fall you will greatly reduce the overwintering population. Repeat your slug bait application again in the spring just as the eyes start to sprout. The fall and then spring treatments should help to eliminate most summer damage.
Voles are types of field mice that love to eat hosta crowns, especially in the winter. To prevent vole damage, place traps along vole runs or put rodent bait in the area. (Make sure other animals can't get the bait as it is very poisonous). Or, get a cat that likes to hunt. And once again, keep the garden free of debris so that the voles don't have good nesting places. Especially clean up debris from ornamental grasses as voles love to build nests in old grass.
Deer can ravage a hosta garden in very little time. To repel deer you can spray the hosta foliage with hot pepper wax, dust the foliage and entire garden with bloodmeal, sprinkle mothballs around the garden, and spray with Liquid Fence (a mixture of garlic, rotten eggs, and soap). Vary your plan of attack and start out doing these things weekly for a few weeks in the spring and then repeat something each month. In time the deer will change their traffic pattern and avoid the garden completely.
Foliar nematodes can be another problem although they will never kill the plants. Yellow to brown streaks may show up between veins in July through September indicating that the nematodes were feeding. The further south you are, the sooner the damage will appear. Good culture is the best solution to prevent plants from becoming too badly affected. To prevent the spread of nematodes, clean all tools when cutting, dividing, or trimming from one plant to another. Also avoid overhead watering as the nematodes can be spread by splashing water. Do not compost the leaves as the nematodes may live in the compost. And remember, nematodes will always flow and collect wherever the water runoff goes. Keeping hostas uphill from other plants can help to prevent nematodes infestations. And keep an eye on hostas in low lying or wet areas as these will be the first plants to show damage.
If a plant becomes infected and it can be easily replaced you might want to destroy the entire plant. Spraying with Diazanon or hydrogen peroxide (1/2 cup of 3% H202 per gallon used as a foliar drench) can be effective at killing some nematodes but will not kill them all and should be repeated 2 or 3 times every 10 to 14 days. Orthene may reduce the active nematode population by about 60%, but none of these chemical treatments kill the eggs. The best way to destroy nematodes and the eggs in an infected hosta is to soak the entire plant in a warm water bath. Soak for 10 minutes in a 120F warm water bath or 5 minutes in a 130F bath. After soaking, immediately rinse with cold water to stop the cooking process.
Hosta Virus X (HVX) Information
Hosta Landscape Uses
Plant Hostas with ferns, woodland anemones, Astilbes, toad lilies (Tricyrtis), Lamium, Pulmonarias, Tiarellas, and other shade loving plants. Use Hostas as specimens or accents, ground covers, edging plants, or background plantings . Plant small Hostas in rock gardens or containers. For a care free bulb garden place tulips or other spring bulbs around the base of Hostas. As the old bulb foliage begins to die away the new Hosta foliage will hide them.