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    Save the Date: Perennial Plant Society’s 30th Plant Sale is April 4, 2020, 9 a.m. – 1 p.m. at the new Expo 3 Building at The Fairgrounds Nashville. Here’s where you can find the newest varieties of perennials, shrubs, vines and annuals from local growers, along with long-time, never-fail favorites, ready for spring planting. Learn more at the PPS website.

     

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Remove English ivy from trees

The large trees around our home are covered with English ivy. Is there a way to keep it from growing up into the limbs of the trees?

P1040778 (2)English ivy growing up into trees (and another invasive creeping vine, wintercreeper euonymous) are most evident now, when the trees are bare. It’s this time of year when you can see just how quickly and how thickly those vines – which are evergreen — can climb into the tree canopy. Left to grow, English ivy vines can engulf the tree within a few years.

Once the vines have grown up into the limbs, there is no quick and easy way to get them down. The vines will have grown stout trunks that continue to reach up and branch out as they cling to the bark. The National Park Service, which has an interest in keeping English ivy from displacing native flora on public lands, suggests several methods for controlling the vine. It likely will require a combination of manual, mechanical and chemical methods. Continue reading

Star of Bethlehem: pretty weeds

What are the little white six-petal flowers that come up in the lawn every spring? We see more of them each year.

Star of bethlehem 2You are probably referring to Star of Bethlehem, which pops up in airy clusters from clumps of grassy leaves about mid-spring. The small (about 1 inch) flowers open in the morning and close by sunset, and flowering lasts two to three weeks. If you are trying to cultivate a weed-free expanse of lawn, you likely will decide before long that this delicate white flower – small and sweet-looking in one or two little clumps — can be a weedy nuisance.

The plants, which are an imported species, grow from small bulbs, and reproduce by seed but primarily by formation of bulblets that grow at the base of the parent bulb, and each bulblet produces a new plant. After it blooms, the plant dies back and remains dormant until next spring, but even though the growing period is short, the plant is aggressive, and will quickly take over an area of the lawn or supplant native vegetation. The flowers and bulbs are toxic and can cause vomiting, diarrhea, shortness of breath, pain, swelling and skin irritation.

The most effective way to get rid of Star of Bethlehem is to dig up the bulblets – each and every one – before the foliage dies back. This is not an instant fix, but may reduce the number of plants in your lawn over time.

Star of Bethlehem is native to North Africa, parts of Eastern Europe and western Asia. In Tennessee (where The Garden Bench calls home), it’s ranked as a “lesser threat” by the Tennessee Exotic Pest Plant Council. The USDA Forest Service has clear guidelines about how to handle this bulb: “Do not plant this species and eliminate the plant if possible.”

Dayflower gives gardens the blues

QUESTION: There’s a weed spreading through my perennial bed, under the trees and even growing out of a pile of stepping stones in my yard. It has small, two-petal blue flowers and long, pointed leaves. What is it? And more importantly, how can I get rid of it?

DayflowerIt sound like you are describing Asiatic dayflower, a weedy annual that grows and spreads quickly and will consume anything in its path if you allow it to proceed. It blooms summer into fall, opening its flowers in the morning (it actually has three petals; two blue and one smaller petal that’s smaller and more pale) and closing up tight by late afternoon. It reproduces from seeds dropped each year, but it also spreads vegetatively, rooting at the leaf nodes on moist soil. Common Asiatic dayflower is in the same family as spiderwort.

Dayflower grows in a variety of conditions, but really spreads aggressively in moist, shady spots. As explained in the Illinois Wildflowers database site, “At favorable sites, the Asiatic Dayflower forms colonies that can exclude other species of plants.”

Dayflower patchSo yes, you may want to try to eliminate dayflower from your garden. It won’t be easy. Glyphosates (Roundup and other non-selective herbicides) don’t faze it, apparently. Gardeners who have struggled with it say that it’s easy to pull out of the ground, but even if you think you’ve gotten every single leaf, stem and root, it likely will come back. It’s easiest to pull up when it’s young and small. Diligence is advised.

Here are some comments I read in a forum at Dave’s Garden as I researched Commelina communis:

“It seems to grow several inches over night and can overwhelm an area in little time.”
“Invasive as they get — one of my biggest pests!”

“This plant is a superweed!”

But let’s end with a couple of good things to know about Asiatic dayflower and its blue blooms: Usually, flowers we call “blue” are closer to violet or purple. The flowers of Asiatic dayflower are truly blue, a color that is found in few other plants. And a commenter at the Dave’s Garden forum says this: “It is extremely invasive; but at least it is edible. The young leaves and stems can be added to salads or boiled for 10 minutes and served with butter.”

Don’t let English ivy ‘leap’

English ivy has covered a chain link fence along our property line, but it’s also getting into a garden bed a climbing up a tree. How can I control it?

English ivy is good for covering ugly fences; not so great when it climbs up into trees.

English ivy is good for covering ugly fences; not so great when it climbs up into trees.

Gardeners have a saying about English ivy: “The first year it sleeps, the second year it creeps, the third year it leaps.” It can be slow to get started, but once it gets going, it quickly leaps out of bounds.

If you are using English ivy to cover an otherwise unsightly feature or to control erosion on a slope, the Southern Living Garden Book suggests trimming the edges back with hedge shears or a rugged mower two or three times a year. Ivy growing up a fence or wall can also be sheared with a hedge trimmer to look neat.

Early winter is a good time to remove ivy that is growing up into trees. Garden expert Judy Lowe (who has penned several garden how-to books for our region) suggests cutting the vine at the base with loppers or a pruning saw. In the spring, the dead vine may fall out of the tree, or you may need to cut and pull down the dead portions.

 

Yarrow: too much of a good thing?

QUESTION: I’ve heard that yarrow is a great drought-resistant perennial, but don’t know anything about growing it. Is this a good time of year to plant it? Is it planted from seeds, or is it better to buy transplants?

It’s true. Yarrow (Achillea millefolium) is a tough and persistent perennial plant that tolerates drought. In fact, it needs well-drained soil to grow well, and if it stays too wet (if it’s planted in heavy clay, for instance) it can rot. Yarrow has fragrant, fern-like leaves and large clusters of tiny flowers. In full sun it grows 2 to 3 feet tall; it will bloom if it’s planted in light shade, but it won’t be as showy. Pests usually leave it alone, and it’s not affected by diseases.

Back to it being a tough and persistent plant: More than one source I checked calls yarrow “invasive.” “Most yarrows spread aggressively into every nook and cranny possible, to the point where one begins to wonder if a mistake has been made in choosing the plant to begin with,” says Felder Rushing in his book, Tough Plants for Southern Gardens.

For that reason, those in the know don’t recommend it for direct-sowing into the garden. Plant transplants, and let the seed-sowing take care of itself later. Better still, cut back the flowers before they go to seed. It will still spread, because yarrow produces lots of creeping rootstock while it’s growing. When you have a big patch of yarrow and decide it’s time to share, divide it by digging up a clump and passing it along or replanting it in another location.

Other names, by the way, include millefoil, woundwort, carpenter’s weed, devil’s nettle and nosebleed, after the old wives’ tale that if a young girl tickles her nose with yarrow and it starts to bleed, it proves her lover has been faithful.

Picture perfect

Photographer and author Matthew Benson is passionate about gardens, and equally passionate about photographing them. His new book, The PhotoGraphic Garden (Mastering the Art of Digital Garden Photography) focuses on the two fundamentals, photo (light) and graph (form). It’s a how-to book, with suggested “assignments” to put lessons into practice, but also a book full of beautiful garden photography that makes you want to sharpen your own photographic skills.

I talked with Matthew by phone a couple of weeks ago. Here’s what he had to say:

From the Garden Bench: What’s the most important thing to think about when you’re photographing a garden?

Matthew Benson: It all begins with light. My advice to anyone thinking about photographing is to really be disciplined about shooting in the right light. Early in the morning is best. Later in the day the light is also nice, but the plants are not as nice. The interesting thing about that early time of day is to witness a quality of light that most people don’t usually see, and certainly not in the garden. Colors are most radiant. That beautiful morning light streaking through a garden and waking things up is just beautiful.

GB: What are the best ways to “use” that light in the garden?

MB: Backlight everything – shoot into the sun, not with the sun on your shoulder behind you. And think about using it in different ways. Follow the light through the garden. Allow the light to direct you through the garden as you photograph. Use a scrim to filter light. Bounce light into things using reflectors, to get a certain quality.

Try to resist shooting in bad light. There is no Photoshop tool to mimic the quality of light.

GB: What about the “graphic” part of taking photographs?

MB: The graphic part is the marvel of some of the plant forms, not only their colors but their shape. Learn how to really “see” botanical form. A big part of it is learning how to see like a camera. Don’t come into the garden and stand there and point your camera and shoot away. Seeing like a camera means understanding that the camera sees the world more interesting. It allows you to edit out things, adjust exposure, to drop focus. You are using the tool to create something original and intriguing for the mind. And it makes us look at the garden differently. When we see something we don’t see all the time, we look at it more.

GB: What recommendations do you have when it comes to choosing a camera?

MB: That’s the technical side of the book. Learn your camera, understand how to use it. Having a good macro lens is important. The camera sensor is more important than megapixels. The bigger the senor, the better the quality of the image. Newer cameras are really focusing on image quality. Also consider the speed of the lens. A camera with 1.4 lens speed, when you’re shooting in the garden, means you can shoot in very low light without a tripod. A fast lens is important. 2.8 is as high as I would go. Lenses that are 2 and under are great. But really, the best camera to have is the one you have with you.

Matthew is a contributing editor to Organic Gardening magazine. The PhotoGraphic Garden is published by Rodale, $24.99.

 

Definitely not stars in your lawn

QUESTION: Every year, the small white flowers called star-of-Bethlehem pop up in our lawn. The flowers are cute, but they’re everywhere! It makes an ugly lawn. How can I get rid of it?

Star-of-Bethlehem: Get rid of it if you can.

This time of year, star-of-Bethlehem shoots up in lawns, on creek banks, in wild meadows. They are indeed everywhere – even in gardens, where unsuspecting gardeners may plant them because they are a pretty little wildflower. The bad news is that once they get a foothold in your lawn, they are tough to eradicate.

Star-of-Bethlehem is a cool-season perennial that grows from small bulbs. The foliage resembles wild garlic, and the small white flowers each have six petals. The bulbs multiply rapidly, and are spread easily. After it blooms, the plant dies down and remains dormant until next spring.

As you might expect, it’s considered an invasive exotic here. The plant is native to North Africa, parts of Eastern Europe and western Asia. UT’s Institute of Agriculture notes that it has become a weed problem on athletic fields and golf courses. Even more bad news: the flowers and bulbs of star-of-Bethlehem are poisonous.

You could try digging it up, but that would be a monstrous task because you need to get every little bulb. UT Extension has a list of control products (most of which are to be used only by professionals). There may be very little you can do except wait it out, and don’t spread them around. The USDA Forest Service is very clear about this: “Do not plant this species.”

 

Periwinkle: Bigleaf can be a big problem

QUESTION: This vine (in the photo) is growing behind the boxwoods in front of our house. I’ve never seen it before. Is this something I should keep or get rid of?

Variegated Vinca major (bigleaf periwinkle) is a major pest plant.

Get rid of it, if you can. It looks like variegated bigleaf periwinkle (Vinca major), and left to grow on its on, will scramble and snake its way across everything in its path. This plant, considered an ornamental groundcover by some, was brought here from Europe more than three centuries ago.

It has pretty little blue or lavender pinwheel flowers in spring, but that’s not enough reason to keep it around. According to the Tennessee Exotic Pest Plant Council, the vine has crept in to open and dense canopied forest, forming mats and “extensive infestations” by vines that root at the nodes. They consider it a “significant threat” in the state, and note that it’s also considered invasive in several other southern states, and in California and the Pacific Northwest.

If your “infestation” is still fairly small, I suggest pulling it up, roots and all, if you can. You’ll probably have to pull it several times before it’s all gone. I never recommend chemical controls, but you can read what TNEPPC suggests here.

One of the nice features about the Tennessee Exotic Pest Plant Council’s web site is that they suggest alternatives for the invasive plants you might be considering for your landscape. So, instead of periwinkle, TNEPPC recommends using these natives:

Wild Blue Phlox (Phlox divaricata) and Creeping Phlox (Phlox stolonifera). Both attract bees and butterflies. Creeping phlox does best in the more acidic mountains of East Tennessee.

Several grass-like sedges make good groundcovers for shady places: Seersucker sedge (Carex plantaginea) has puckered light green leaves. Silver sedge (Carex platyphylla) has slightly puckered, light blue-green foliage. Blue wood sedge (Carex flaccosperma) has silvery blue foliage and can do well in wetter sites.

Partridgeberry (Mitchella repens) is a small creeping vine with tiny, glossy, deep green leaves, pairs of white fuzzy flowers in early June, and bright red berries. It grows in shade, and needs acid soil. Birds like it.

Golden Ragwort (Packera aurea [ Senecio aureus ]) has dark, evergreen foliage that colonizes as a groundcover and yellow flowers in early spring. Attracts bees and butterflies.

Marginal Woodfern (Dryopteris marginalis) is an evergreen fern that likes shade and moist soil.

 

Banish the Bradford pear

QUESTION: When should Bradford pear trees be pruned? Is now a good time? How far back should you prune them?

Bradford pear trees are the first to flower in spring, but they are not a good choice for landscape trees.

I’ll answer the last question first, and echo the thoughts of many landscape and forestry experts who believe that these trees should get just one pruning cut – about an inch above the ground.

Seriously, Bradford pears (Pyrus calleryana Bradford’) are not good landscape trees, no matter how lovely they are this time of year. They live fast and die young – a 25-year-old Bradford pear is probably near the end of its life. Because their heavy limbs grow at narrow angles, they tend to split apart. And because they shoot up so quickly and easily, this import from China has been placed on alert as a possible threat by the Tennessee Exotic Pest Plant Council. So, is it time to reconsider?

But back to the question: It’s good to prune trees in late winter, while they’re still dormant. As you are no doubt aware if you’re in Middle Tennessee, “late winter” now seems to mean the same as “spring,” and most things are no longer dormant. So if you need to prune, do it now, before the tree leafs out fully and you can still see the branch structure easily.

Really, though, wouldn’t you rather have something else? Landscape professionals suggest a couple of good native alternatives to the Bradford pear: downy serviceberry (Amelanchier arboria), which has white flowers in spring, dark green foliage in summer and red berries in the fall; and Fringe tree (Chionanthus virginicus), white flowers, green leaves, small blue-black fruit enjoyed by birds in the fall.

Either would be better than a Bradford pear, guaranteed.

 

The trouble with winter creeper

QUESTION: A vine with dark green, oval leaves and thick woody stems is growing up through the middle of my shrubs. It seems to grow all year. What a nuisance! How can I get rid of it?

Winter creeper euonymus grows in sun or shade, can cover slopes, fences, trees, and is hard to get rid of once it's established.

It sounds like you are describing winter creeper euonymus, an evergreen that can sprawl along the ground (or on slopes, where it can help control erosion) or it can climb and attach itself to trees, walls and other surfaces with aerial roots.

You may see it described as “tough” or “aggressive,” and come to understand that to mean you’ll have a hard time getting rid of it. Indeed, it’s a non-native invasive plant, brought here from  the other side of the world in the early part of the last century. The Tennessee Exotic Pest Plant Council lists it as a “lesser threat,” but a threat nonetheless.

Cutting it down, pulling it out and digging it up are the best ways to begin the attack on winter creeper. Where digging doesn’t work, try cutting it back and applying glyphosate herbicide (such as Roundup) as a 2-percent solution (8 ounces per 3-gallon mix) in water to the stump that’s left. You’ll have to keep doing this, and you’ll have to be careful not to get the herbicide on the surrounding plants.

After the vine has been removed, the best way to keep it from returning is to keep an eye on the area and pull up individual seedlings as soon as you see them.

Small space, big harvests

Is that really possible? Maybe, and there’s a new book in the Complete Idiot’s Guide series that’s here to help. The book is The Complete Idiot’s Guide to Small-Space Gardening, and the author, Chris McLaughlin, provides quite a bit of good information on how to make the most of whatever plots or pots you have available. It’s published by Alpha Books; the price printed on the book is $19.95; at the Web site idiotsguides.com it’s listed as now $12.97.

Cover the ground, not the daffodils

QUESTION: What groundcovers can be used that will allow daffodils to come up in the spring?

Spring bulbs will grow through English ivy, but there are better groundcover choices to use.

Several plants used as groundcover permit spring-flower bulbs to grow through. Nashville-area garden specialists offer a few recommendations:

Ajuga, or bugleweed (Ajuga reptans). To some people this is a nice groundcover, to others it’s a weedy nuisance. It can be aggressive, but in the right spot it might be just what you need.

Periwinkle (Vinca minor), grows in shade, is green all year, and has pretty blue or white flowers in spring. Please note: Vinca minor is listed among the invasive exotic plants in Tennessee. Please use responsibly.

Daffodils will also push up through English ivy (Hedera helix), but because it, too, is an invasive exotic that can climb trees and displace more desired species, I would never suggest planting it in the landscape.

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