Hosta FAQs: What can go wrong?
While there are lots of places online to find information about hostas (see our links), and of course a number of books you can buy for ready references, we didn't feel that there was a good place online for FAQs (Frequently Asked Questions), as experience with the American Hosta Society's Facebook page has shown. We hope you find this useful. The good stuff is at Part I. Here are FAQs on hosta problems. You may also want to check the "Hosta Health" part of the Lingo page.
Click on the little ˅ at the end of each line to expand (and then collapse) the answers.
Hail hit my hostas! What do I do?
Oh hail no! A hailstorm can be devastating to the appearance of a hosta garden, but fortunately the plants will survive. In general, resist the temptation to cut off all the foliage, although in severe circumstances (and early in the season) that may be the best answer. Any foliage still attached is still feeding the plant, as awful as it might look. Now is the time that they will need a good dose of fertilizer; they will respond by making new leaves. As the new leaves come in, consider again whether you want to cut off the tattered ones. And remember that next year will probably be better.
My hostas got bigger the first two years but are now getting smaller. What’s wrong?
The answer is almost certainly tree root competition. You made a lovely home for your hostas under shade trees, but the trees found that space a really good place to send roots. Some trees, like red maples (Acer rubrum) are particularly notorious for strangling hostas. Others (including black walnuts) are not nearly as bad. Some gardeners resort to growing most of their hostas in pots rather than in the ground, but that’s an extreme solution. One simpler solution is to space your hostas out a bit more so that once or twice a year you can, with a sharp shovel (and being mindful of spreading HVX), cut a ring around each hosta to sever the roots growing into it. One bad solution is to pile a foot of soil all the way around a tree (even worse, using some barrier cloth), which can smother the tree.
How do I keep deer from eating my hostas?
Deer are smart, and deer are stupid. You have to train them that your garden is off-limits. The obvious solution is a fence, six to eight feet tall. Large dogs can also help. But if that’s not practical (and for most of us, it isn’t), you need be vigilant and use a cycle of products that make the hostas unpalatable. Train them that your hostas are "off limits" all season long.
How do I keep rabbits from eating my hostas?
Your hostas may never be bothered with rabbits (they like to eat other stuff in our garden), but you may want to try a spray based on hot pepper (use caution), or spread some moth flakes (naphthalene) around plants they’re bothering. Note that where deer eat the leaves and leave the petioles behind, rabbits will cut off the petioles at the base and eat their way up to the leaves. Groundhogs, if you have a problem with them, will eat it all (but usually not that many). Rabbits are also fond of bloom scapes (before or after flowering), so hybridizers beware! Mice may eat seed pods, but generally nothing else. (Voles are a different problem.)
How do I keep slugs from eating my hostas?
The gray garden slug (classic slug of the eastern US, not the leopard slug, which has spots) is a serious pest for hostas. There are several ways to control them. One is a commercial “pellet” poison based either on a chelated iron phosphate (not as animal-friendly as the product claims to be) or on metaldehyde (harder to find now, and not very animal-friendly either). If you have animals that like to eat out of your garden, the toxicity of these product can be of concern, especially if you spread the product too thickly. Spread thinly and you’re not likely to have any collateral damage to animal life. The current version of "Bug-geta" uses ground sulfur instead, but I don't know how effective it is.
How do I keep voles from eating my hostas?
Voles (not moles, which are carnivorous insect-eaters) can cause rapid and serious damage by eating the hosta roots right up into the crown of the plant. The evidence is divisions that weaken and even fall over, and pull away from the plant with no roots. You may find the little tunnels, just underground (or under your mulch) where the little guys are moving around. You have three options: spray your property with castor oil to repel them, poison “bait” stations to eradicate them, or barriers around your hostas to keep them away from the crowns. (Having an outdoor cat can be a helpful third option.) For barriers you can create collars using hardware cloth. These should go into the ground about 5" and stick above the ground/mulch by 1". They should be big enough around so that most hosta roots will stay inside. An alternative to this is to buy inexpensive wire wastebaskets, dig a hole and plant the basket with 1" above ground, and plant the hosta in the basket. You can use a good spray paint to paint the rim of the basket to camouflage it.
How do I keep nematodes from eating my hostas?
Foliar nematodes (not to be confused with beneficial nematodes that are sometimes used to treat problems with grubs, etc.) are microscopic worms that invade the hosta leaves and leave brown streaks on infested leaves, weakening the plants and making the leaves unattractive. The nematodes can move about in the soil to get to other plants, or ride along on drops of water where one plant touches another.
What about HVX (the dreaded Hosta Virus X)?
That's a topic that deserves its own page, Part IIa.
Have I got rot?
See the Lingo page (under Hosta Health) for a description of the serious rotting diseases, which may be caused by fungus or bacteria.
Dew you know
what to dew?