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Archives for September 6, 2017

Burning questions about pests, weeds and more, as summer yields to fall

Early September is the time of transition from summer’s hot weather to the cool-down of fall. With the changes that begin to happen about now come a lot of questions from North Texas gardeners. I’ve assembled the ones I’m being asked most often.

How late can I apply pre-emergent weedkillers and still have good results against winter weeds?

You’re there now! You need to get Team, Dimension, Halts or Balan granules out in the next several days to prevent germination of annual bluegrass (Poa annua), rescuegrass and ryegrass. This is your only chance to deal with these grassy weeds. Once they germinate you will not have another opportunity until this time next year (next generation of the weeds).

Make an additional pass over the lawn to control broadleafed weeds such as henbit, chickweed, dandelions and clover. Apply Gallery granules for the non-grassy weeds. These products are most likely to be found at independent retail garden centers.

Why is my St. Augustine yellowed in big patches? It’s been that way for much of the summer.

In most cases that’s been gray leaf spot. It’s a fungal leaf spot that also appears on runners. The gray-brown lesions are BB-sized and irregularly diamond-shaped. Gray leaf spot has been especially troublesome this year, and many people have reacted by applying nitrogen fertilizer in an attempt to green up their turf. Unfortunately, gray leaf spot is exacerbated by nitrogen in hot summer weather, so those people have really added to their own turf troubles.

At this point, if you’re still seeing the disease actively attacking your lawn, hold off one or two more weeks before you fertilize your turf. If you’re one who applied nitrogen fairly recently, perhaps you shouldn’t fertilize again until next April. There are fungicides that will help with gray leaf spot, but it’s very late in the season to be applying them. Like some of the pre-emergent weedkillers, they’re most commonly sold at independent retail garden centers.

What is wrong with my roses? They didn’t bloom very well last spring, and they’ve looked worse and worse all summer. What can I do to help them now?

Odds are high that your roses have rose rosette virus. It’s a fatal virus that somehow has decided that the Fort Worth/Dallas area is where it needed to appear in epidemic proportions. It’s been so bad over the past five or six years here that there are almost no healthy roses remaining. Sales have dropped to almost zero. First symptoms are rank-growing, extremely thorny “bull” canes, but later they become stunted. RRV is transmitted great distances by wind-borne microscopic mites. There is no control for the virus, and there is also no prevention or control for the mites.

About all you can do is replace the roses immediately with some other type of shrubs or flowers. Hopefully the massive research now underway will find a work-around, genetic or otherwise, for this devastating virus.

Why are the leaves of my morning glories, marigolds and other plants turning tan, then dried and crisp?

Spider mites will do that. They feed on the undersides of the leaves, sucking the green color out of the leaves in the process. When the damage becomes severe you will see fine webbing in the leaf axils, but by then it’s usually too late to save the plants. If you see the tan mottling, thump a suspect leaf over a sheet of white paper. If you see tiny paprika-colored specks starting to move about on the paper, those are the mites.

Apply a general-purpose insecticide that is also labeled for spider mites to control them. Spray the bottom leaf surfaces as well as the tops. Check the plants a couple of days later to be sure you’ve gotten good control.

There is an insect pest that causes similar damage to another group of plants. Lace bugs attack pyracanthas, Boston ivy, sycamores, bur oaks, chinquapin oaks, azaleas, American elms and boxwoods, among others, turning their leaves the same pale tan color. However, on the backs of their leaves you’ll see black, waxy specks. Those specks are the excrement of the adult insects.

They began doing their damage in June, and there may not be any more of the adults still present on the plants. Systemic insecticides do a good job of preventing this damage if applied in early summer. There is no call to treat this late in the season.

“What is causing the rows of holes in the leaves of my cannas?”

That would be canna leafrollers. The larvae tie the leaves together while they’re still tightly rolled. They feed on the leaves much as if you drilled a hole through a rolled-up newspaper. When the leaves unfurl they look like they’ve been sprayed with a machine gun. A systemic insecticide applied as a soil drench in late spring usually will prevent this damage from happening.

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Gillitts Nursery spring gardening tips


Ants, termites – use Kemprin or Koinor

Moles, crickets – use Koinor

Worms – use Kemprin


Small broad leaf – use MCPA

Large broad leaf – use Lawnweeder

Fungus in lawn

Dollar spot and leaf spot – use Odeon 720SC


Protect with Chronos and Koinor. A good spray with Chronos every two weeks will protect from black spot and powdery mildew. Using Koinor – it is systemic, meaning it goes down into the roots and feeds up into the stems, thus protecting the rose.

Kemprin can also be used for rose beetles. Insect control “aphids� on citrus use Kemprin also for leaf miner.

Ideally Koinor should be applied in late August to September.  Citrus trees should not be in flower when applying Koinor.  If in flower, or in fruit, apply Kemprin mixed with a little Sunlight liquid as a wetter.  Fruit is fine after two week waiting period. – Compiled by Lynn Doherty.

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Water wise gardening tips | Southlands Sun

Take up water harvesting for your garden

Collected rainwater and water used in the home can be used in the garden as long as you follow some guidelines about what is in the water you collect. Even if you have infrequent rainfall, the use of rain-harvesting guttering will divert water into collection tanks. This takes the pressure off the water supply as harvested rainwater and grey-water from your home allows you to use less of the piped supply.

Using household water you would otherwise throw away can be a source of many litres of water for your garden.

Research ways to use grey water, which runs from baths, washing machines, dishwashers and the the like, into pipes and can be diverted and used to water your garden.

It is important however that if you are going to use grey water you ensure it doesn’t contain bleach, disinfectants or stronger cleaning agents which could harm soil structure and damage plants. Household soaps and most detergents are harmless to plants, but if you are unsure find out before buying a cleaning product.

Look after the soil

One of the first casualties of water shortages is the soil moisture which can undermine soil quality. Adding mulch and other organic matter like compost, can help prevent loss of soil moisture and even improve your soil. If you are able to, collect cuttings and vegetable waste from the kitchen and create your own compost. Adding any water retentive matter helps prevent water from evaporating before it has a chance to be absorbed by the plants.

Similarly, mulching flower beds, adding grass cuttings or water-retentive granules to compost at the base of plants, shrubs, trees and even hanging baskets and planters will allow the plants to make efficient use of the water you are able to provide them.

Choose plants wisely

Some plants need less water than others to grow successfully. Consider replacing plants which have died down due to water shortages with others that need less water.

South African indigenous plants have had years to adapt to the conditions in our country and normally do better in water scarce gardens than exotics which need extra watering to mimic more lush climes.

Water precisely

Using a watering can, watering around plant bases while leaving other areas dry can help to limit weed growth while it ensures the precious water goes where it is most needed.

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Gardening tips for smoky weather

SPOKANE, Wash — Gardening tips for this smoky weather in the Pacific Northwest.

Smoke could slow down plant growth.

“The smoke is going to slow down the plants a little bit because obviously, we see the difference in the sunlight and they feel, the plants feel the difference in sunlight as well,” said Urban Horticulture Coordinator of WSU Master Gardeners, Tim Kohlhauff.

The air will not ruin your vegetables, so you can still eat those tomatoes you are growing.

“The smoke and even if there’s a little bit of ash build up on the plant that won’t do any damage, just wash it off like you normally would,” said Kohlhauff.

The smoke and ash will break down in the soil and become fertilizer.

“These are forest fires and because this is all natural material that’s floating around us, as it settles on the soil, the micro-organisms are going to actually work that into the ground and it could be fertilizer for next year, so there might be something good that’s come out of all this,” said Kohlhauff.

When the smoke clears, you should wash the ash off of your plants.

“If there’s some people in areas where ash is actually building up on the plant, that will block the sunlight getting through and slow them down, so you might want to wash the ash off the leaves when we get through all of this,” said Kohlhauff.

One thing to know is plants actually handle the smoke better than people do.

“Worry about yourself first, take care of yourself and your garden will take care of itself,” said Kohlhauff.

© 2017 KREM-TV

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Garden Help: Tips for preparing your yard for hurricane season – Florida Times

While writing this article, Hurricane Irma is approaching the Florida coast. Gov. Scott declared a state of emergency for all 67 counties in the state of Florida. By the time this article is in print, we will know what areas of Florida will be impacted.

After experiencing Hurricane Matthew last year, we are all hurricane weary. Many homeowners were displaced and are just now getting their homes back in order. Folks in Texas are just beginning the recovery phase of rebuilding their community after being hit by Hurricane Harvey. Northeast Florida residents that were affected by Matthew can attest that the rebuilding phase is a long and grueling process.

Whether Hurricane Irma is impacting our area this weekend or not, it’s timely during hurricane season to review some preparations to make before the storm.


Gutters, storm drains, landscape swales and ditches, wet or dry detention ponds and retention basins are all part of our stormwater system to move water away from streets and neighborhoods during heavy rains.

One way you can help is to keep storm drains clear of debris so they can function properly. Do not put grass clippings, pet waste or other debris down the storm drain — water only.

Clear gutters of leaves, branches and other debris to make sure water from heavy rains has free movement away from the house. Make sure gutters are firmly attached and directing water away from the home. If there are no gutters on the home and the water pours off the roof in a concentrated area, consider placing pavers in the runoff area to reduce soil erosion.

If you have rain barrels, leave the spigots open. Rain barrels that are connected tightly to the gutters will collect water quicker than it can be discharged and could create problems by backing up into the gutter. If this is the case, disconnect the gutter from the rain barrel, allowing the barrel to overflow from the top. Rain barrels that are not full can be blown away, so either fill with water or move them to a secure area like the garage.


For starters, sprinkler systems should be in the off mode. One thing hurricanes are known for is lots of rain, so too much of a good thing is not good for plant roots. More water at this stage will only promote disease problems. Saturated soils coupled with high winds lead to uprooted trees, especially trees with shallow root systems. Most irrigation systems have a rain shut-off device but this dries out quickly and will trigger the irrigation system to run even though the soil is still saturated. So don’t depend on this device to regulate the irrigation system. Make sure it is off and reset to automatic when soils dry out.


Walk around the landscape and look for problem areas. Are there trees or shrubs that are too close to the house? Branches from these plants may damage shingles or siding with the constant wind movement during a storm. Prune these away from the house now and get the debris out of the landscape before the next storm.

Are there trees that look unhealthy? Perhaps the tops are dying back, indicating a root or trunk problem. Large trees with multiple trunks that have V-shaped branch angles are potential hazards because branches are weak and often split during storms. Is there a target in the event the tree falls or the branch breaks off? If there is a questionable tree with a target, have a certified arborist come and check out the tree before it’s too late. To find a certified arborist in your area, check Be an informed consumer by reviewing pruning recommendations at University of Florida’s Environmental Horticulture website at Ask for a written proposal of the work that will be done on your tree and request that a certified arborist is on site when trees are pruned. If they suggest topping the tree or making flush cuts to remove branches, call another arborist. Ask for ISA certification and proof of insurance to cover personal and property liability.


Do not prune trees and leave debris on site if a storm is imminent. It’s better to take a chance and leave the tree intact if you can’t secure the pruned branches or get them off site before the storm. Branches and other debris become dangerous projectiles during a storm.


Remove broken, hanging or dead palm fronds. Do not remove leaves that are just slightly brown on the tips, as this practice can lead to severe nutrient deficiencies which could affect the life of the palm. In addition to dead fronds, remove flowers and fruits, as they could become airborne. If someone suggests pruning in a V-shape, referred to as a “hurricane cut,” find another company. Constant removal of leaves will result in a condition referred to as “pencil top” (trunk narrows just below fronds) which makes the trunk area very weak during storms. In addition, the leaves around the center help protect the bud during high winds. Pruning should not go above a horizontal line through the base of the fronds. So when completed, the fronds should extend out from nine to three o’clock resembling the shape of an umbrella. Spikes should not be used to climb any palms or any trees. If you have pole pruners, you can make a lot of the necessary cuts on smaller palms and avoid excessive pruning and potential disease problems.


Mulch will frequently be washed away from plant beds, so prepare to replace it once the storm is over. If beds are soggy, wait for them to dry out some before mulching. Rubber edging materials will sometimes help to hold in the mulch but may also hold in water. Try placing pine straw along the edges of plant beds to help contain bark mulch.


Although September is the month we traditionally put out our last lawn fertilizer application, do not spread fertilizer if a tropical storm/hurricane is imminent or prior to a heavy rain. Little if any of the fertilizer will benefit the lawn as the fertilizer will be washed away, moving into the storm drain or any adjacent water bodies and contributing to algal problems


Anything outside should be secured or moved to a sheltered area. Small container plants/hanging baskets can become airborne, as can patio umbrellas and furniture. People that have pools often put their patio furniture in the pool. That won’t work for containerized plants but you could place them in a sheltered area like the garage. If they are too heavy to move, try placing them behind a hedge close to the foundation of the house and lay them flat.


If we get a lot of rain, be prepared for bugs and other critters looking for higher ground to make their way into homes. Ants, roaches and snakes will escape saturated soils because they are in the survival mode. There are plenty of products available to control the insects and a sticky board may be the best bet for snakes.

We may get lucky and avoid this one but it’s better to be safe and prepare for the worst. For more info on preparing for hurricanes, go to the UF Extension program’s disaster preparation website at

Terry Brite DelValle is a horticulture extension agent with the Duval County Extension Service and the University of Florida/IFAS.

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WEEKS 1-4: Continue planting evergreens now.

WEEKS 1-3: Cuttings of annuals can be taken now to provide plants for overwintering.

WEEKS 1-3: Herbs such as parsley, rosemary, chives, thyme and marjoram can be dug from the garden and placed in pots now for growing indoors this winter.

WEEKS 2-3: Begin readying house plants for winter indoors. Prune back rampant growth and protruding roots.

Check for pests and treat if necessary. House plants should be brought indoors at least one month before the heat is normally turned on.

WEEKS 2-4: Except tulips, spring bulbs may be planted as soon as they are available. Tulips should be kept in a cool, dark place and planted in late October.

WEEKS 3: Poinsettias can be forced into bloom for Christmas if they are moved indoors now to a sunny windowsill. Each night, they must be kept in a cool, dark place where there is no light for 14 hours. This must continue until proper color is achieved in six to 10 weeks.

WEEKS 3-4: Perennials, especially spring bloomers, can be divided now. Enrich the soil with peat moss or compost before replanting.

WEEKS 3-4: Divide peonies now. Replant in a sunny site and avoid planting deeply.

WEEKS 3-4: Lift gladiolus when their leaves yellow. Cure in an airy place until dry before husking.


WEEKS 1-4: Cool season lawns are best fertilized in fall. Make up to three applications between now and December. Do not exceed rates recommended by fertilizer manufacturer.

WEEKS 1-4: If soils become dry, established lawns should be watered thoroughly to a depth of 4 to 6 inches.

WEEKS 1-4: Begin fall seeding or sodding of cool season grasses. Seedbeds should be raked, dethatched or core-aerified, fertilized and seeded. Keep newly planted lawn areas moist, but not wet.

WEEKS 2-4: Lawns may be top dressed with compost or milorganite now. This is best done after aerifying.

WEEKS 3-4: It is not uncommon to see puffballs in lawn areas at this time.

WEEKS 3-4: Newly seeded lawns should not be cut until they are at least 2 or 3 inches tall.


WEEK 1-2: Egyptian (top-setting) onions can be divided and replanted now.

WEEKS 1-2: Sowing seeds of radish, lettuce, spinach and other greens in a cold frame will prolong fall harvests.

WEEKS 2-4: Keep broccoli picked regularly to encourage additional production of side shoots.

WEEKS 2-3: Pinch out the top of Brussels sprout plants to plump out the developing sprouts..

WEEKS 2-3: Harvest herbs now to freeze or dry for winter use.

WEEKS 2-3: Tie leaves around cauliflower heads when they are about the size of a golf ball.

WEEKS 3-4: Pinch off any young tomatoes that are too small to ripen. This will channel energy into ripening the remaining full-size fruits.

WEEK 4: Sow spinach now to overwinter under mulch for spring harvest.


WEEK 1: Pick pears before they are fully mature. Store in a cool, dark basement to ripen.

WEEKS 3-4: Bury or discard any spoiled fallen fruits.

WEEK 4: Check all along peach tree trunks to just below soil line for gummy masses caused by borers. Probe holes with thin wire to puncture borers.

WEEK 4: Paw paws ripen in the woods now.

WEEK 4: Check all along peach tree trunks to just below soil line for gummy masses caused by borers. Probe holes with thin wire to puncture borers.


WEEKS 1-4: Autumn is a good time to add manure, compost or leaf mold to garden soils for increasing organic matter content.

WEEKS 1-2: Monitor plants for spider mite activity. Reduce their numbers by hosing off with a forceful spray of water.

WEEKS 3-4: Seasonal loss of inner needles on conifers is normal at this time. It may be especially noticeable on pines.

The gardening calendar is supplied by the staff of the William T. Kemper Center for Home Gardening, which is located at the Missouri Botanical Garden in St. Louis. (

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Work on V&A community garden begins

Work has begun on Dundee’s VA Museum community garden.

Volunteers reacted to a call to arms and helped place plants and flowers into the community space on Tuesday morning.

The garden itself was created by both green fingered volunteers and professional designers.

According to VA Dundee director Philip Long, the community garden and the VA itself are for the whole city, not just for tourists visiting the development.

Mr Long said:  “We’ve worked very hard to help make the VA something that is at the heart of the community.

“It’s been very important for us to be out there working with people across the communities to get a sense of what their aspirations and hopes are for VA and how it might make a difference to their lives.

“So, while we are still quite a bit off opening, we are already realising projects like this. We’ve been working with communities across the city, the region, and country to hear what people want and to help generate opportunities for people.

“We want VA Dundee to be something which makes a difference to people’s lives.

“It (VA Dundee) has always been rooted in the city. One of the major aims of the VA Dundee is to help make a difference to this city.”

VA Dundee communities producer Peter Nurick said Tuesday’s development has been two years in the making and is testament to the hard work of local people and designers.

He said: “This project started with a co-design process involving adults in the city living with and recovering from a range of complex mental health conditions.

“Now, we’re having volunteers from across the city involved in the planting and hopefully long term maintenance of the community garden.

“This project has been about connecting the VA Dundee with the city. The garden’s location, directly opposite the museum, is a real tangible link between the city and the museum.”

Volunteer Joyce Hannah Cuthbert, from the Scottish Association for Mental Health, has been involved throughout the garden design.

She said: “I could nearly cry I’m so happy.

“It’s so fantastic to see.

“It looks so different when you’re actually here.

“This will be a good place to sit and chill and to meet people.”

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Isamu Noguchi’s Creative Playground Designs Exhibit at SFMOMA

Isamu Noguchi, Playground equipment for Ala Moana Park, Hawaii, circa 1940. Courtesy of the Isamu Noguchi Foundation and Garden Museum, New York /Artists Rights Society (ARS), New York. Photography by Kevin Noble.

From innovative jungle gyms to experimental ideas utilizing piled earth, Isamu Noguchi’s forays into playground design were varied and forward-thinking. Providing a careful look at these explorations is an exhibition at the San Francisco Museum of Art, “Noguchi’s Playscapes,” originally organized by Mexico City’s Museo Tamayo Arte Contemporáneo in collaboration with New York’s Noguchi Museum. For the SFMOMA exhibition, Jennifer Dunlop Fletcher acted as curator. Items on view include painted plaster maquettes of play equipment, wood models of playground designs, sketches, and images of children playing on realized work. “The exhibition includes not only works designated as play structures, but also works that influenced his outdoor play pieces, such as set props for dances, abstract works on paper, and designs for memorials,” Dunlop Fletcher writes.

Fay S. Lincoln, Image of Noguchi’s playground equipment for Ala Moana Park, Hawaii, c. 1940. Courtesy of the Isamu Noguchi Foundation and Garden Museum, New York / Artists Rights Society (ARS), New York.

Included is a bronze model for an unrealized New York playground proposal that included no equipment, only sculpted earth to function as slides and play sites. “Imagine experiencing this in an urban environment in 1941!” Dunlop Fletcher writes. Although Noguchi’s playground designs were often met with rejection during his lifetime, a few examples of impact should be noted. In his only fully-realized design, Atlanta’s Piedmont Park features his boldly colored play equipment alongside a spiral tower, both evocative of earlier designs. Legacy of his vision can also be found in New York’s Rainey Park, where colorful mounds serve as supports that slides cascade down. That playground is blocks from the Noguchi Museum, where an exhibition currently examines his time at the Poston War Relocation Center. Included in that show is his unrealized design for recreation areas at the internment camp, further fodder for examining the legacy of the sculptor’s vision, both built and not.

Isamu Noguchi, Slide Mantra Maquette, c. 1985. Courtesy of the Isamu Noguchi Foundation and Garden Museum, New York / Artists Rights Society (ARS), New York. Photography by Kevin Noble.

“Noguchi’s Playscapes” is on view at the San Francisco Museum of Modern Art until November 26, 2017.

“Self-Interned, 1942: Noguchi in Poston War Relocation Center” is on view at the Noguchi Museum in New York until January 21, 2018.

Isamu Noguchi, Jungle Gym; set element of Erick Hawkins’s dance “Stephen Acrobat,” 1947. Courtesy of the Isamu Noguchi Foundation and Garden Museum, New York / Artists Rights Society (ARS), New York. Photography by Kevin Noble.

Isamu Noguchi, U.S. Pavilion Expo ’70, 1968. Courtesy of the Isamu Noguchi Foundation and Garden Museum, New York / Artists Rights Society (ARS), New York. Photography by Kevin Noble.

Isamu Noguchi, Contoured Playground, 1941, cast 1964. Courtesy of the Isamu Noguchi Foundation and Garden Museum, New York / Artists Rights Society (ARS), New York. Photography by Kevin Noble.

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University of Georgia breaks ground on Alice H. Richards Children’s …

Last Friday, sunny skies and light breeze welcomed University of Georgia and State Botanical Garden of Georgia officials as they broke ground on the Alice H. Richards Children’s Garden.

It was a project nine years in the making, and as of Sept. 1, the two-and-a-half acre green space in the botanical gardens is officially growing.

“We’re very excited. This will be a new opportunity to engage children,” UGA Director of Office of Service Learning Dr. Shannon O’Brien Wilder said.

Director of the State Botanical Garden Jennifer Cruse-Sanders began the ceremony by greeting attendees and distributing thanks to all contributors towards the garden, which is set to officially open in early 2019.

“The Children’s Garden will be an engaging, safe, hands-on space that will allow children to discover and explore nature,” she said.

Cruse-Sanders said this garden intends to incorporate three guiding principles in its programming: nature as a teacher, connecting with nature through arts, science and literacy education and a healthy lifestyle.

These lessons are rooted in the garden’s design, which consists of a canopy walk in the trees, treehouses, creature habitats, hands-on activities and an underground zone. The plan has been architected by Athens-based Koons Environmental Design and Allstate Construction.

“I am confident that their collaboration will result in a children’s garden that will not only become an important part of our community, but will be one we will be excited to showcase to the entire state,” Cruse-Sanders said.

Geoffrey P. Cole, chair of the botanical garden board of advisors, followed Cruse-Sanders and discussed the immense anticipation and donations from the garden’s staff.

“We’ve been eagerly anticipating this day,” Cole said.

Laura Meadows, the interim vice president of UGA’s Public Service and Outreach thanked the support from the university and the garden staff.

UGA President Jere W. Morehead celebrated these efforts as well and emphasized the educational opportunities yet to come.

“Certainly the Alice H. Richards Children’s Garden is going to be a wonderful and inspiring destination for everyone in the University community and in the city of Athens,” Morehead said.

Morehead extended additional gratitude to the Richards family, whose $1 million contribution in 2007 initiated the dream of the garden.

Jim Richards and his son Chase Richards honored the garden after Jim Richard’s mother, Alice, a cherished mother and grandmother and avid gardener.

Alice H, Richards was also a charter member of the State Botanical Garden Board of Advisors. She specifically desired for the grant to do something significant for the garden and children alike, Jim Richards said.

“We’re excited to see it actually begin to bloom,” Jim Richards said.

The Richards family, from Carrollton, hope to have every member come and visit once the garden completes in honor of their grandmother.

“She would be so proud,” Chase Richards said.

UGA and the garden’s board of advisors have raised $4.3 million out of the $5 million project so far, and hope to have $10,000 by Sept. 8.

“This is going to be a great space,” Director of Communications for UGA Public Service and Outreach Kelly Simmons said.

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New research finds potential antibiotic cure for fire blight

Last year, researchers at the University of Georgia Extension Service noted that fire blight appeared on a growing number of pear trees, but this year there may be hope yet for infected trees.


Scientists say that fire blight is the oldest, most serious and most perplexing bacterial fruit tree disease. It is caused by the bacteria Erwinia amylovora, and it is extremely common.

It can affect any of the plants in the Rosaceae family. Apple, crabapple, pyracantha, quince, hawthorn, loquat and cotoneaster are all particularly vulnerable. Fire blight appears as a reddish, watery ooze coming out of a branch or trunk cankers as soon as the infected plant begins active growth.

Infected flowers and stems turn brown or black and wither, and the bacteria spreads through rain and pollinators. Copper products can be sprayed to reduce the bacteria’s ability to survive and reproduce.

A recent discovery in Connecticut could now offer growers a new line of defense against the disease. Scientists created the first antibiotic for controlling fire blight in 1950 called Streptomycin. Unfortunately, after about 20 years the bacteria started developing a resistance to the antibiotic. Since then, scientists have continued searching for new ways to control fire blight.

“I feel it’s my responsibility to help the growers to come up with some ways to combat this disease,” Quan Cheng, the assistant plant pathologist and bacteriologist at the Connecticut Agricultural Experiment Station, told WSHU Public Radio Group. “As a plant pathologist, I often start my research from a disease problem that really has a big economic value.”

Estimated annual losses of apple trees to fire blight are over 100 million, and these trees contribute about 14 billion dollars to the national economy each year.

Cheng serves as one of the seven authors on a recent study that proved there is new technology that can help fight fire blight. The result of this research was the Antisense Peptide Nucleic Acid- Cell Penetrating Peptide. This uses a special strand of Peptide Nucleic Acid (PNA), which looks just like DNA.

This PNA breaks into the cells of the bad bacteria and scans the bacteria’s DNA to find the essential gene that keeps the bacteria alive. This antibiotic can be made to kill only the bad bacteria, unlike others which kill both good and bad.

“The short answer is, I borrowed some old ideas from animal pathogens, combined with some of the uniqueness in plant agriculture and came out with these research findings,” Cheng told WSHU Public Radio Group. “So, they will come and bind to those essential genes, and once the essential genes are bound by these molecules, those genes will be destroyed.”

According to Cheng, this selectivity also means fire blight is less likely to develop a resistance to the bacteria, and even if it eventually does, it will be an easy fix.

“The beauty of this technique is you can design the sequence, you can write a code,” Cheng told WSHU Public Radio Group. “And if the bacteria change their sequence as a result of resistance, you can rewrite the code so you overcome this resistance.”

Cheng says that while it may take a while to get this technology into the hands of growers, since the technology has been proven effective, other plant pathologists will be able to use it.

“To me it opens a new, a whole area in plant disease management,” Cheng told WSHU Public Radio Group. “I can see that it also has a great potential to be used in controlling many devastating plant diseases.”

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