Monday, March 11, 2019

Early Detection of Rose Rosette Disease

Article Courtesy of:
Alan Windham, Professor and UT Extension Specialist
Mark Windham, Distinguished Professor
Frank Hale, Professor and UT Extension Specialist Department of Entomology and Plant Pathology

Rose rosette is a serious virus disease of roses. It is spread primarily by a microscopic mite. Successful management of rose rosette disease (RRD) involves early detection of symptoms.


a. Hyper (excessive) thorniness.
b. Distorted flower buds.
c. Affected tissues may be red, but they are sometimes green.
d. Strapped (thin) leaves.
e. Thickened stems.


f. Plants should be inspected at one- to two-week intervals for symptoms during the growing season.
g. Do not wait until the plant has multiple symptomatic shoots or a rosette before digging, removing and bagging the plant. Delayed action could jeopardize other roses in your garden as the microscopic mites* that vector RRD are more numerous on symptomatic tissue. 

 *Eriophyid mite courtesy: Gary Bauchan, USDA-ARS

h. Herbicide damage may appear as strapped, bunched or dwarfed leaves but not as swollen canes or hyper-thorniness.
i. Shoots damaged by chili thrips may have dwarfed, distorted leaves. Leaves may become blackened as they mature. 
j. Fasciation of stems has not been associated with RRD. Fasciation may be found in many herbaceous and woody plant species. It is the result of several flattened stems growing together. The cause of fasciation is unknown. 

• If multiple symptoms are present, even one shoot, remove the plant; losing one plant is preferable to losing the rose garden.
• Send a sample of live, symptomatic foliage to your Extension office for positive confirmation. This will aid you with future diagnoses.
• For more information on rose diseases, see A Guide to Rose Diseases and their Management at

Monday, March 26, 2018

April Gardening Tips from UT Institute of Agriculture

April is the month for gardeners. All the world seems to be in bloom and gardening enthusiasts are just waiting for assurances that the last frost for the spring has passed. For much of the state April 15 is the “safe date” but estimates are available from the National Weather Service for specific locations.

Jason Reeves, curator of the University of Tennessee Gardens, Jackson, offers these tips for coordinating a few of your outdoor efforts as you struggle to install landscape plants and gardens:

·  Tomatoes, peppers, eggplant, okra, basil, sweet potatoes pumpkin and gourds resent cool temperatures, so despite your enthusiasm, wait until night temps are consistently above 50 degrees F to plants. Wait also for the ornamentals vinca, lantana, ornamental sweet potatoes and caladiums.

·  Prune spring-flowering shrubs (azaleas, flowering quince, Forsythia and Loropetalum) soon after they finish flowering, but only if they need it. Selectively cut old or unruly branches by reaching deeply into the shrub leaving no visible stub, making the cut just above a joint. This pruning method will keep them from looking like meatballs.

 ·  A good option for Loropetalums that have outgrown their space is to tree-form them. They can easily be limbed up by removing lower branches. Loropetalum ‘Crimson Fire’ is a new dwarf from that has proven to be hardy in all but the coldest part of Tennessee. As with all Loropetalums, they are best planted in spring or summer in insure proper establishment before the winter months. It will mature to 3-ft tall, and can be seen growing at the UT Gardens in both Knoxville and Jackson.

·  Kerria japonica, also known as Japanese kerria or yellow rose of Texas, often has dead branches. Follow them to the base to cut them. Remove older branches the same way to keep the plant looking good. Older, overgrown or neglected plants can be cut to the ground for rejuvenation.

·  Azaleas often show symptoms of lace bug and spider mite infestations during the hot months of summer. This damage can be prevented by a one-time, early application of the systemic insecticide imidacloprid. This insecticide should be poured in liquid form around the root system as the flowers fade, spreading the active ingredients throughout the plant tissue where it remains effective through the growing season. Bayer Advanced Tree and Shrub Insect Control is a common brand that contains this safe and effective insecticide. Always follow label directions when applying any pesticide.

·  You can direct seed easy-to-grow flowering annuals and vegetables. Some easy flowers to grow from seed include marigold, zinnia, sunflowers and cosmos. Beans, peas, corn and okra are some easy direct sow vegetables, while dill, basil and cilantro are some easy direct sow herbs.

·  Try the annual moon vine, Ipomoea alba, this year to attract sphinx moths to your garden.
Nick the hard seed coat carefully with nail clippers and soak in water overnight to hasten germination.

·  Spring is a good time to freshen up the mulch in your landscape. Remember not to pile it around the trunks of your trees and shrubs. If using a pre-emergent herbicide, be sure to apply it before spreading your mulch to prevent the sunlight from breaking it down. It also forms a more effective barrier when allowed to bond with soil particles. Remember it is not necessary to fertilize well-established trees or shrubs. If you are trying to encourage faster growth on new plantings, a balanced granular fertilizer scattered on the soil surface is effective. Be careful not to overdo it. Tree spikes or drilling fertilizer into the root zone is unnecessary and expensive.

·  Cut back any woody perennials that may need it, like rosemary, rue, lavender, Santolina and Artemisia. If done before the danger of frost has passed, new growth may appear, and a freeze can kill that new growth and sometimes the entire plant.

For additional tips, visit the UT Extension website: and click on the menu link to “Publications.” Enter the term “landscaping” or “gardening” in the search engine. You can also contact your local county UT Extension agent.

Tuesday, May 16, 2017

Want Some New Blooms for 2017? 

Check out some of these beautiful, award winning perennials!

Best New Perennial Flowers of 2017

Article Courtesy of George Weigel-

A showy new ornamental grass, a new dark-leafed succulent, and new disease-resistant phlox and beebalms headline the list of perennial flowers debuting in 2017.
Let’s take a look at some the best of the best of these perennial newcomers showing up now in catalogs and primed to go on sale in garden centers this spring:

Japanese forest grass SunFlare
Credit: HarkAway Botanicals
Japanese forest grass SunFlare
Pennsylvania author and “perennial diva” Stephanie Cohen is a fan of the basic, compact, arching, shade-preferring Japanese forest grass (a.k.a. Hakone grass), but she’s particularly enamored by an even more compact and colorful variety called SunFlare coming to garden centers by fall 2017.
“It starts out with a colorful, showy chartreuse that blends well with other perennials,” Cohen says. “The morning sun makes the leaves glow a golden yellow with deep crimson flecks in the blades. But this little grass has one more trick up its sleeve. The chartreuse and gold mingle, and its fall flare bursts into a rainbow of color with a simmering burnt-orange and one of my favorite fall colors, burgundy-red.”
SunFlare grows 12 to 18 inches tall and does best in well-drained soil (no wet clay), ideally in morning sun and afternoon shade. Cohen also likes it for use in a container. It’s being introduced by Canada’s HarkAway Botanicals.
Sedum ‘Firecracker’
Fans of dark foliage will love this new drought-tough, succulent groundcover for hot, sunny spots.
“I love the foliage saturation of purple,” says Erica Shaffer, manager at Highland Gardens in Lower Allen Twp., which plans to carry ‘Firecracker’ this spring. “I can never have enough purple in my garden.”
Introduced by Michigan’s Perennial Resources, ‘Firecracker’ plants grow only about 6 inches tall in a dense, tight mound that doesn’t flop apart like some sedums.
Small pink flowers in late summer are a bonus.
Foamybells Fun and Games
For afternoon-shade garden beds, check out this new three-version series of foamybells (Heucherella) that rate as the favorite new perennial of Carleen Vorisek, the perennial manager at Ashcombe Farm and Greenhouses in Monroe Twp.
Vorisek especially likes the colorful, deeply lobed foliage of the ‘Red Rover’ variety. “This plant stays green in summer but changes to a copper-red color in the fall,” she says.

Foamybells Leapfrog, left, and Red Rover
Credit: Proven Winners
‘Leapfrog’ has wider chartreuse leaves with burgundy markings (“mellowing” to green and purple by summer), while ‘Hopscotch’ has leaves that emerge red in spring, soften to green in summer, then turn bronze-red in fall.
All three varieties grow 10 to 12 inches tall with creamy white bottlebrush flowers in May. All also are coralbell/foamflower hybrids of U.S. native perennials.
Anemone Wild Swan
Breeders keep trying to extend the bloom time of perennials. This Scottish hybrid is one of the longest yet, producing its white petals with the unusual soft-lavender back sides nearly non-stop from June through October.
I saw Wild Swan in plantsman David Wilson’s Lower Paxton Twp. garden last summer, and it was happily blooming away in July’s dry heat.

Anemone Wild Swan
The plant is related to the better known Japanese anemone that blooms in early fall, but this one blooms much earlier (as well as longer) and is more compact at 18 to 20 inches tall. Anemone Dreaming Swan is also new and very similar.
These anemones are sterile and so don’t seed around. (Best in morning sun, afternoon shade.)
Liriope Purple Explosion
Liriope is a grass-like, workhouse perennial that’s usually used as a groundcover for its versatility and hard-to-kill reputation.
Purple Explosion is a new variety that turns the corner on liriope to make it an attractive bloomer, worthy of ornamental use alongside the coneflowers, lavenders and salvias of the garden.
The variety not only produces significantly more purple flower spikes than older liriopes, but it produces them earlier, longer and on stems that poke up more prominently above the bladed green foliage.
Plants grow 10 to 12 inches tall, and clumps spread slowly – no over-aggressive “runners” as some liriopes produce. (Full sun to part shade.)
Yarrow New Vintage series

Yarrow New Vintage Red, left, and Violet
Credit: Penn State Trial Gardens
This four-color series of heat- and drought-tough yarrows from Darwin Perennials was one of the best-performing perennials of any kind in the 2016 Penn State Trial Gardens in Lancaster County.
The Red and Violet colors did particularly well in 2016’s hot summer, earning nearly perfect scores from trial Director Sinclair Adam.
New Vintage plants grow to a compact 12 to 14 inches tall. They bloom for weeks in late spring, then rebloom nicely in late summer, especially if you cut spent flower stalks back to the ground after the first bloom fades. (Best in full sun.)
Phlox Fashionably Early series
Amanda Bastiaanse, a perennials grower at wholesale Quality Greenhouses near Dillsburg, likes this new four-color line of early-flowering, disease-resistant, native tall garden phlox introduced by Michigan’s Walters Gardens.
“Old-fashioned garden phlox, while they have beautiful flowers, tend to have a short bloom time and are prone to all kinds of fungal diseases that make them look ugly much of the season,” says Bastiaanse. “Many of the new hybrid phlox that we have grown in the last couple years, including the Fashionably Early series, are really great improvements in terms of the length of time they flower and disease resistance. These bloom a little earlier, too.”
The Fashionably Early series includes ‘Princess’ (fuchsia pink), ‘Flamingo’ (lavender pink), ‘Crystal’ (white), and ‘Lavender Ice’ (lavender with a pink eye). Plants grow 28 to 36 inches tall and perform best in full sun.
Coneflower Butterfly ‘Postman’

Coneflower Butterfly Postman
Credit: Plants Nouveau
This new heat- and drought-tough U.S. native offers both a short, 18-inch size and bright-red blooms as opposed to the traditional lavender-pink of coneflowers.
“Fiery red flowers and a contrasting brown cone make for a lovely combination in this compact, long-blooming addition to the Butterfly series,” says Angela Treadwell-Palmer, co-owner of Plants Nouveau, which is introducing the plant. “It’s a true red with slightly dropping petals. ‘Postman’ stands out in any planting like a red-lighted beacon.”
Treadwell-Palmer says it looks especially nice with blue ornamental grasses, white- and orange-flowered perennials and coarsely textured leaves like ‘Black Ripple’ elephant ear. Best in full sun.
Monarda Bee-You series
Treadwell-Palmer also likes this new pollinator-friendly line of beebalms with the excellent disease resistance, compact 18- to 24-inch size, and range of five colors.
“These new beebalms are mildew-free, covered in flowers, the perfect size, and available in colors to bring any outdoor space to life,” she says. “Bees, butterflies and hummingbirds can’t resist their sweet nectar and fragrance.”

Monarda BeeTrue
Credit: Plants Nouveau
Varieties include ‘Bee-Merry’ (coral pink), ‘Bee-Free’ (maroon), ‘Bee-Happy’ (red), ‘Bee-Lieve’ (pale pink), and ‘Bee-True’ (purple). Best in full sun.
Lamium Purple Chablis
Ashcombe’s Vorisek suggests this Proven Winners newcomer as a colorful groundcover in shady to partly shaded areas.
She says lamium Purple Chablis has “silver-green foliage that’s attractive all during the growing season. The purple flowers add flare.”
Plants grow only 10 to 12 inches tall and bloom a long time, starting in late spring and running most of the way through summer.
“It would be a great option for shade perennial containers, too,” Vorisek adds.
Purple Chablis is heat- and drought-tough, isn’t bothered by deer, and tolerant of nearly full sun as well as nearly full shade.
Rudbeckia American Gold Rush
The black-eyed susan variety ‘Goldsturm’ is one of America’s best-sellers, but it’s increasingly troubled by a septoria leaf-spot disease that blackens its leaves many years in late summer.
American Gold Rush is a new rudbeckia variety from Illinois’ Intrinsic Perennials with much narrower leaves and far better disease resistance. It’s also debuting as an HGTV brand under the name Everlasting Sun.
American Gold Rush plants bloom just as heavily as ‘Goldsturm’ with 3-inch golden, daisy-like flowers that produce over about 2 months from mid to late summer. Plant height is just under 2 feet. (Best in full sun.)

Ligularia King Kong
Credit: Walters Gardens
Ligularia ‘King Kong’
If you like both dark leaves and very big ones, you’ll hit the double jackpot with ‘King Kong,’ a hefty new shade-preferring perennial introduced by Michigan’s Walters Gardens.
‘King Kong’ is similar to an existing head-turner called ‘Britt-Marie Crawford,’ except this one’s leaves are nearly twice as big – checking in around 16 inches across. They’re also leathery and nearly black.
Plants grow about 3 feet tall, produce a few stalks topped with golden flowers in summer, and do best in damp soil and afternoon shade.

Friday, April 1, 2016

Peony-One of the Most Beloved Flowers

Peonies are outrageously beautiful in bloom, with lush foliage all summer long. These perennials may live longer than you do—some have been known to thrive for 100 years. The plants require little maintenance as long as they are planted properly and establish themselves; they do not respond well to transplanting.
Peonies take your breath away every spring. They’re hardy to Zone 3 and grow well as far south as Zones 7 and 8. In most of the country, the rules for success are simply full sun and well-drained soil. Peonies even relish cold winters, because they need chilling for bud formation.
Peonies make fine sentinels lining walkways and a lovely low hedge. After its stunning bloom, the peony’s bushy clump of handsome glossy green leaves lasts all summer, and then turns purplish or gold in the fall, as stately and dignified as any shrub.
In mixed borders, peonies bloom with columbines, baptisias, and veronicas, and combine well with irises and roses. Plant white peonies with yellow irises and a froth of forget-me-nots; set off pink peonies with blue Nepeta or violets.


  • Grow peonies in deep, fertile, humus-rich, moist soil that drains well.  Soil pH should be neutral.
  • The soil will benefit from the addition of organic material in the planting hole. If the soil is heavy or very sandy, enrich it with compost. Incorporate about 1 cup of bonemeal into the soil. Tamp soil firmly.
  • Peonies are not fussy but choose your location wisely as they resent disturbance. Provide shelter from strong winds. Plant away from trees or shrubs as peonies don’t like to compete for food and moisture. Space them three to four feet apart for good air circulation.
  • Peonies like full sun, and though they can manage with half a day, they bloom best in a sunny spot.
  • Peonies are usually sold as bare-root tubers with three to five eyes, divisions of a three- or four-year-old plant.
  • Plant peonies in the fall: in late September and October in most of the country, and even later in the South. (If you must move an established plant, this is the time.)
  • Peonies should be settled into place before the first hard frost. Spring-planted peonies just don’t do as well, experts agree; they generally lag about a year behind those planted in the fall.
  • Dig a generous-sized hole, about two feet deep and two feet across in well-drained soil in a sunny spot. If the soil is heavy or very sandy, enrich it with compost. Incorporate about one cup of bonemeal into the soil. Tamp it firmly.
  • Set the root so the eyes face upward on top of the firmed soil, placing the root just 2 inches below the soil surface. (In southern states, choose early-blooming varieties, plant them about an inch deep, and provide some shade.)
  • Then backfill the hole, taking care that the soil doesn’t settle and bury the root deeper than 2 inches.
  • Water thoroughly.
Tip: Don’t plant too deep! In most of the country, the peony’s eyes (buds) should be no deeper than 1-½ to 2 inches below the soil line!

Like children, young peonies take time to develop. They usually need a few years to establish themselves, bloom, and grow.
Peonies thrive on benign neglect. Unlike most perennials, they don’t need to be dug and divided.
  • Spare the fertilizer. Work the soil well before you plant, mixing in a little fertilizer, and that should be enough.
  • If your soil is poor, the time to apply fertilizer (bonemeal, compost, or well-rotted manure) is early summer, after the peonies have bloomed and you have deadheaded. Don’t fertilizer more than every few years.
  • Help the stems. If peonies have any structural weakness, it is their stems, which are sometimes not strong enough to support their gigantic blossoms. Consider three-legged metal peony rings that allow the plant to grow through the center of the rings.
  • Deadhead peony blossoms as soon as they begin to fade, cutting to a strong leaf so that the stem doesn’t stick out of the foliage. Cut the foliage to the ground in the fall to avoid any overwintering disease.
  • Don’t smother peonies with mulch. Where cold temperatures are severe, for the first winter after planting you can mulch VERY loosely with pine needles or shredded bark. Remove mulch in the spring.
Peonies are generally very hardy. They are prone to Verticillium wilt, ringspot virus, tip blight, stem rot, Botrytis blight, left blotch, Japanese beetle, and nematodes.
Many gardeners wonder why so many ants crawl on the peony buds. They are eating nectar in exchange for attacking bud-eating pests. Never spray the ants; they’re helping you nurture peonies to bloom.
Tip: Peonies make wonderful cut flowers, lasting more than a week. For best results, cut long stems when the buds are still fairly tight.

Article Courtesy of The Farmers Almanac