Banishing ‘leaflets three’

QUESTION: What’s the best way to get rid of poison ivy?

Growing up where pavement and neatly trimmed lawn were the modern idea of landscaping, I didn’t encounter poison ivy until I became a real gardener. But by the time  I did learn the mantra (Leaflets three – let it be!) I knew to keep well away from it. Unfortunately, it seems to show up everywhere these days.

The best way to deal with poison ivy is, of course, to treat it very carefully. Fitzroy Bullock, a professor at Tennessee State University’s Cooperative Extension Program, has written a fact sheet on identifying the vine and dealing with it in the landscape.

When you find the sweet little seedlings in garden beds (often at the edges of the lawn, along fence lines, places that don’t get regular mowing), you can dig them out, roots and all, and dispose of them. Wear long sleeves and gloves to do the job. If you use disposable gloves, you can throw them away when you’re done, and avoid the possibility of accidentally getting the plant’s irritating oil on your skin. Some have suggested using a plastic newspaper bag as a glove, of sorts. Put your hand in the bag, use it to pull the vine out of the ground, then peel the bag off, inside out, with the vine inside.

If it’s a big vine with a well-established root system, it’s a bit harder to get rid of. Cut it as close to the ground as possible, and to keep it from growing back, immediately treat the stem with a garden herbicide that contains glyphosate (such as Roundup). Don’t spray the vine itself, and be careful not to let the spray get onto other plants, because glyphosate – or even a drift from the poison – will kill or damage most every green thing it touches.

Even after it’s dead, a large vine can be a problem. The toxic leaves dry up and fall on the ground, and later, after the aerial roots that have held it up begin to die, the whole vine could fall. Dispose of dead leaves and vines carefully, because the toxin is still present.

You may need to apply a second helping of herbicide if the vine begins to grow again from the stump. Apply herbicide again when the new, young leaves have opened fully.

If you are sensitive to the plant and accidentally make contact, expect intense itching, rash and blisters – not a serious situation, but certainly bothersome for a few days. It’s a good idea at any rate to wash your skin with soap and water after a day in the garden.

Keep ‘Annabelle’ standing

QUESTION: What is the best way to secure Annabelle hydrangeas to keep the beautiful blooms from breaking in the wind and rain? And why do these beautiful flowers do so poorly when they’re cut for an arrangement? – Debbie

'Annabelle' is among the stars of summer.

It’s true. The big, heavy bloom heads of Annabelle hydrangeas make an impressive statement in the summer, but whip them around with a strong wind or pelt them with heavy rain and they can flop over like big, wet rags. Sometimes the stems break, and that spells the beginning of the end for the lovely white flowers.

The best way to keep them standing is to prop them up. Judith King, who writes a Web site devoted to hydrangeas, has several suggestions. She says you can plant them next to a decorative fence, plant three Annabelle shrubs together so they prop each other up, or, early in the spring, surround each plant with a short wire cage. As they leaf out and grow, the foliage hides the cage, and all you see is your tall, lovely hydrangeas, happily standing.

One cultural practice to consider: Some gardeners cut the stems of Annabelles close to the ground in the fall. Since these hydrangeas bloom on new growth, they’ll grow and bloom just fine next summer, but the stems will not have had a chance to thicken. If you leave the stems 18 to 24 inches tall, those stouter stems will help support the newer branches and blooms next year. 

As for why the flowers sometimes do poorly after they’re cut (they sometimes wilt within an hour or two), Judith King says this seems to be caused by a sticky substance that clogs up the stem. Try this:

When you go out to cut hydrangeas, take a container of water and put the stem in water immediately after you cut it. Back indoors, boil more water and pour it into another container. Cut the hydrangea stems to the desired length, then stand the stems in the hot water for 30 seconds. Immediately put them into room temperature water in an arrangement. King says it works like a charm.

Good gardening events:

- Head out now to “Gardening A to Z,” the Davidson County Master Gardeners’ annual Field Day. There are demonstration gardens, how-to booths, a plant sale, food sale and more, and admission is free. It’s going on from 9 a.m. – 2 p.m. today at Ellington Agricultural Center. Maybe I’ll see you there.

 - Also at Ellington, the Middle Tennessee Daylily Society is having its show and sale today. The will be held in the Ed Jones Auditorium at the Ellington Agricultural Center. It’s open to the public from 12:30 – 4 p.m. Plus, MTDS will have more than 1,000 daylilies for sale in many varieties and colors. Double bare root plants valued up to $20 will be sold for $5, says MTDS president Larry Brown. The sale is 10 a.m. – 4 p.m. today.

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Read more garden questions and answers in the Garden Club column at Tennessean.com.

Got moles? They’re all over – or under — my kitchen garden. My next plan of attack will be a castor oil recipe that’s supposed to encourage them to move on. Read about it over at Turning Toward the Sun: A Garden Journal.

Dividing daylilies

When is the best time to separate Stella De Oro daylilies?

'Rosy Returns' is a good choice for a repeat blooming daylily.

Early spring and fall are good times to separate and replant all types of daylilies, including Stella De Oro and other repeat-blooming varieties.

Daylilies (the botanical name is Hemerocallis) are blooming beautifully in gardens in Middle Tennessee. The ‘Stella De Oro’ variety, which is what you usually see growing in sweeping yellow masses around office buildings and in grocery store parking lots, seems to be the most common, but there are other wonderful repeat bloomers to consider. (By the way, you may see this variety spelled ‘Stella d’Oro’ elsewhere. I’m using the same spelling as the American Hemerocallis Society.) ‘Happy Returns’ is also yellow, but a softer, creamier shade than the brassy ‘Stella de Oro.’ ‘Rosy Returns’ has dramatic rose-pink flowers. There are several more.

The repeat bloomers are great because, unlike most other daylilies that bloom for a few weeks and are gone, repeaters will come back throughout the summer — though never as lovely as this first flush of blooms.

Experts at the National Arboretum say that most varieties can go for four or five years before they need to be divided. Others also note that repeat bloomers may tend to form bigger clumps, and may need to be divided more often.

When the time comes to divide them, use a garden fork to loosen the soil around the clump, and pry the clump of roots out of the ground. Divide it by pushing two garden forks back to back down into the center of the clump and push the handles apart to separate the roots.

To replant divisions, dig a wide, shallow hole and place the rootball into the hole. Backfill with soil and tamp it into place, then cover the soil with an inch of mulch. Water thoroughly. You can cut the foliage back to about 12 inches.

This is a good time to mention that the Middle Tennessee Daylily Society is having its show and sale next Saturday (June 18). The show theme is “Magnificent Daylilies – 21 Years of Celebrating Daylilies in Middle Tennessee.” The event will be held in the Ed Jones Auditorium at theEllingtonAgriculturalCenter, at the intersection ofHogan RoadandTrousdale Road. It’s open to the public from12:30 – 4 p.m.

Along with the show of floral designs and displays of hundreds of daylilies, MTDS will have more than 1,000 daylilies for sale in many varieties and colors. Double bare root plants valued up to $20 will be sold for $5, says MTDS president Larry Brown. The sale is from10 a.m. – 4 p.m.

Plant sale, garden tour

Head to Springfieldthis morning for the plant sale and garden tour sponsored by the Robertson County Master Gardeners. The plant sale is 9 a.m. – 2 p.m.(rain or shine) at the Robertson County Extension office, 408 North Main Streetin Springfield. From 10 a.m. – 2 p.m., five Springfieldgardens in the downtown historic district and Mooreland Estates area will be open for tours. (If it’s raining, the tour will be held next Saturday.)  Tour tickets are $5. To learn more: www.rcmga.org/

The trouble with roses

The leaves on my climbing roses developed little black spots and now all the foliage has dropped off. What is this?

For questions on roses, I always go to the helpful experts at the Nashville Rose Society, and their Web site. It looks like there are at least two fungal diseases that cause black spots on the leaves of roses: one appropriately called black spot, and the other, anthracnose. You can tell the difference by looking at the edges of the spots. Black spot has the feathery margins, which give rise to some of its other names: leaf blotch or star sooty mold.

Both make a rose look really bad for awhile, which is why people who are serious about growing fancy, beautiful roses stick to such a rigid schedule of spraying. Fungicides are to ward off the ugly fungal diseases, pesticides to keep away chewing and sucking bugs.

Both blackspot and anthracnose overwinter on the plant and develop in the incubator of a cool, most spring. Cleaning up around rose bushes (getting rid of dead leaves and decaying matter), pruning out affected canes, giving the rose bushes plenty of air and reducing the amount of time water stays on the leaves can go a long way toward reducing the development of disease spores. Fungicides, applied on a regular schedule in early spring, can help prevent infection.

The problem of dealing with and preventing rose diseases is one reason landscapers and gardeners plant so many of the ‘Knock Out’ varieties, which bloom all summer and are resistant to most of the ugly diseases that plague garden roses.

Which leads to another question a friend asked not long ago:

Are ‘Knock Out’ roses real roses?

I understand the reason for the question, because it does seem impossible, doesn’t it? Given all that you hear about how you have to prune, spray and coddle rose bushes to get them to look their best, how can there be these easy-care upstarts, this ‘Knock Out’ series that seems poised to take over the rose universe? To get a rose expert’s view on the topic, I talked to Anne Owen, a Nashville Rose Society consulting rosarian.

 “They are, in fact, a really true rose, in the genus Rosa,” she said. “The fact that they don’t require spraying for fungal diseases puts them in a category with very few others.”

Most rose enthusiasts, she said, like the challenge of growing the big, show-stopping roses – the ones in striking colors and with exceptional fragrance. And those are the ones that require coddling. “If you want a great big cabbage rose or a big hybrid tea, you’re going to have to spray.”

But a ‘Knock Out’ finds a place even in the most serious rose gardens.

“I think most rosarians have a ‘Knock Out’ or two because they are such great plants,” Owen said.

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This month in the garden: Welcome the blooms, not the bugs: June Landscape & Garden Calendar in The Tennessean.