Slugs feel at home in the hostas

QUESTION: I have hostas in my yard that were beautiful all summer, but they are now riddled with holes. What could have happened to them?

The broad leaves of hostas lure slugs to the shade, where they also find a tasty meal.

When you find holes in your hostas, the problem most likely is snails and slugs say the experts at U.T. Extension. Hostas are shade plants, and slugs and snails are right at home in a shady, moist environment. The large, wide leaves create a shady spot, so they stay in that cozy spot all day and come out at night, climbing up on the leaves to dine.

If you want to see how active they are, try this: place a small board, about six inches wide, beside the hostas where you’ve noticed damage. In the morning, turn the board over and see how many have collected on the underside (and dispose of them as you wish). A gardening friend told me recently that she had set out an old tuna can filled with beer beside the hostas in her garden. The next morning, the can was full of slugs, and she dumped the whole thing into the trash.

The American Hosta Society suggests several solutions for protecting plants from slug dining damage, one of which is to provide something else to eat that might be just as tasty, such as lettuce. A different strategy focuses on placing a barrier around vulnerable plants. Strips of copper on the ground can be effective because slugs don’t like to cross it. Maybe that’s a way to use all those pennies that collect around the house. Table salt sprinkled around the plants also may keep them away, but you probably don’t want to add all that salt to the soil. My friend who lured slugs into a tuna can also said she has tried sprinkling diatomaceous earth around the hostas as a barrier they won’t cross.

The American Hosta Society mentions a couple of poison baits, but also suggests that a 10% solution of vinegar, sprayed on the slugs, stops them in their tracks – but you have to be out there with the spray when they are out, which is usually at night. And finally, a trap: place two boards together with a small stick between them, where the slugs can crawl in and hide in the cool shade. Then, when the slugs are between the boards, remove the stick and stomp. Ewww.

October in the garden: Early-fall tasks in the October Garden Calendar in The Tennessean.

Garden events in Middle Tennessee

Oct. 4 – 5: Tennessee Urban Forestry Conference spotlights “Urban Forestry for Healthy Living” at Ellington Agricultural Center. Landscape designer Tara Armistead leads a tour and workshop on Oct. 4 and delivers the keynote address on Oct. 5. Open to the public; details at http://tufc.com/conference_2012.html

October 6-7: The Tenarky District Convention and Rose Show is at BelmontUniversity. Events open to the public on Oct. 6 include the rose show, 1 – 5 p.m., and a lecture on rose growing basics by Ron Daniels at 2 p.m. On Aug. 7, the rose show is open 11 a.m. – 4:30 p.m.; Cecil Ward lectures on “Loving and Growing Roses in Tennessee” at 2:30 p.m. Here to learn more.

Oct. 16: Perennial Plant Society’s monthly meeting at Cheekwood’s Botanic Hall begins with refreshments and plant swap at 6:30 p.m.; program at 7 p.m. Speaker is landscaper Tina Ramsey on the topic, “Winter Gardening.” Open to the public.

Oct. 19: All About Trees at Warner Park Nature Center. Enjoy a walk in the park while you learn the different species of trees from expert Deb Beazley. 9 – 11 a.m. Call to register (adults only), 352-6299. www.nashville.gov/parks/nature/wpnc

Oct. 27: Pumpkin carving at Shelby Bottoms Nature Center’s Back Porch Picking Party, 1 – 3 p.m. Bring a pumpkin, bring a string instrument, or just plan to relax and enjoy nature while listening to music. Registration required; call 862-8539 or email shelbybottomsnature@nashville.gov. www.nashville.gov/parks/nature/sbnc

Keep Rosemary happy

I have a small  rosemary bush that is thriving, and hope it lives through the winter. What is the best way to care for it so it survives?

Rosemary cuttings can root in water.

More and more, I was hearing gardeners say their rosemary, which does not always make it through winter outdoors in this area, was getting through the cold just fine. Then last year, many gardeners I talked to said their rosemary – which may have been growing for years in the same spot – died. Mine did, too.

Herb experts say that the survival of rosemary can be hit-or-miss. It depends on the kind of winter we have, the kind of rosemary that’s growing in your garden, and even where it’s planted.

If we experience a series of very cold days with very low wind-chill temperatures, rosemary may not stand a chance. If the plant is in the ground on the south side of the house, where it’s protected from a cold north wind, it has a better chance of survival. If it’s near a concrete driveway, brick walkway or a stone wall – anything that reflects a little of the sun’s warmth – there’s an even better chance it’ll make it through unscathed.

It’s best chance is if it happens to be one of the hardier varieties that’s planted on the south side of the house and protected from the wind. The Herb Society of Nashville lists the varieties ‘Arp,’ ‘Hill Hardy’ and ‘Salem’ among the best choices for this area. The National Arboretum adds a few more to the list; check out their choices here.

You may be tempted to dig up the rosemary and bring it indoors for winter, but that’s a bad idea. Rosemary is a shrub and won’t take kindly to the dry air and heat inside the house (which is why so many of those cute rosemary topiaries that people give as gifts die so quickly). If you want to try to bring some of your rosemary inside, you may try to snip a few cuttings and keep them inside in a vase of water, where they may grow roots. Change the water every day or two.

Hostas in the spotlight
Hosta growers, hybridizers and lovers from all over will gather in Nashville next June for the American Hosta Society’s 2012 Convention.  The meeting, June 13 – 16 at the Nashville Airport Marriott, will have a distinctly Nashville flavor with the theme “Hostas, Friends, and Music.” Details on the speakers, programs, panels, tours and more are at the just-launched convention Web site, hosta2010.com.

Here’s a hosta event that’s coming right up: The Middle Tennessee Hosta Society will meet Oct. 27 at Cheekwood, 6:30 p.m. Hosta gardener Cornelia Holland will speak on “Rohdea, the Sacred Lily.” All are welcome to attend.