Central - Spring 2022

Sara Shields, Polozola, Michael, Singh, Raghuwinder, Strahan, Ronald E., Hawkins, Keith, Fontenot, Kathryn, Kirk-Ballard, Heather

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Coral Honeysuckles on Display


Greetings and welcome to the spring 2022 edition of the Central Region Horticulture Hints!

A vine with elongated tubular red flowers.
Coral honeysuckle vine in bloom. Photo by Mark Carriere

Locally, plants in our native and Louisiana Super Plant demonstration gardens at the Dean Lee Research and Extension Center are soon to be in full bloom. One of the plants we are featuring in this edition is the native coral honeysuckle, Lonicera sempervirens. We have the coral honeysuckle growing on a trellis in the native garden, and it blooms almost year-round. Unlike other honeysuckles, this variety maintains a more manageable size, usually between about 6 to 10 feet in length, though it can get a bit larger in some environments. With the smaller size, this variety makes an excellent choice for a fence, arbor or trellis, knowing that you will not need to constantly prune to keep in shape. Coral honeysuckles will tolerate a wide range of light conditions, from full sun to part shade, and they are winter hardy down to USDA Hardiness Zone 4.

As a result of a recent drainage project, our Louisiana Super Plant demonstration bed has been completely redesigned, and we invite you to come take a look. We have planted a mix of annuals, perennials and ornamental grasses, which will continue to grow and bloom through the upcoming spring, summer and fall months.

We hope you enjoy this spring 2022 edition of Horticulture Hints! You are always welcome to join us at one of our gardening seminars or through participation in the Louisiana Master Gardener Program (please see the left column). If you have any gardening-related questions, please contact your local LSU AgCenter extension office.

Dr. Sara Shields
Louisiana Master Gardener State Coordinator
Central Region Horticulture Coordinator


Home Horticulture Resources Available


We all learn differently. Some of us can add something to our memory banks just by hearing it once. Others can pick up a skill just by watching someone else do it a few times. Many of us need to practice using our own hands to master a skill. In truth, most of us learn best when all these learning methods are combined.

While virtual content lacks the hands-on approach, it can provide the auditory and visual components of learning. That is why it has been one of my goals to create video content on horticultural topics that can be watched at any time. The material we have created includes notes on the proper timing of various horticultural tasks, from sowing seeds and planting transplants to grafting pecan trees and establishing shade trees in the landscape. I believe that it can never replace the personal touch of site visits and learning through experience, but it can be very useful in between those events.

We currently have about 30 horticulture videos on our LSU AgCenter Central Region YouTube Channel at https://bit.ly/LSUAgCentralRegion. I suspect that by the time you read this that number will have grown even greater. At the moment our main playlist categories are Fruits and Vegetables, Landscape Plants, Strawberries, Pecan and Trees.

In addition to the Central Region YouTube Channel, did you know that you can also learn more about popular gardening topics by visiting our Central Region Horticulture Website? Find it at https://www.lsuagcenter.com/portals/our_offices/research_stations/deanlee/features/horticulture. The website includes a mix of home gardening articles, video links to our YouTube channel and links to LSU AgCenter publications to fit a range of learning styles.

But we need your feedback! Please let us know what you think about the videos we have already created and what topics you would like to see featured in the future. It is my hope that with your input we can create more relevant content that people will use. If you have ideas or constructive criticism, please email me at MPolozola@agcenter.lsu.edu or give me a call at my office at 318-427-2669.

Michael Polozola, Ph.D.
Horticulture Agent
Pecan Expert


Pretty Pink Phlox for the Garden


A flower bed with pine straw mulch planted with shrubs and a mounded planting of phlox, a plant with light pink flowers.
Prairie Phlox blooming in the native demonstration garden.Photo by Sara R. Shields

If you have not yet visited the native plant demonstration garden at the Dean Lee Research and Extension Center, I would highly recommend you visit this spring. We have several different phlox varieties planted, and they make a tremendous statement in the landscape every spring and summer. One of the plants I would like to call special attention to is the prairie phlox or downy phlox, Phlox pilosa, which is a vigorous evergreen perennial groundcover. This phlox variety stays on the smaller side, usually reaching heights of 10 to 14 inches, and will spread throughout an area as seen in the picture. The plants can be grown in a wide variety of light conditions, from full sun to part shade, and even deciduous shade, and they are winter hardy down to USDA Hardiness Zone 4. They prefer mildly acidic soil that is well drained. Plants should be fertilized in late winter or early spring. As you can see, the native demonstration bed is absolutely covered with these light-pink-colored blooms during the spring months. After they have finished blooming, the plants will go into a period of rest during the summer months, just about the time some of the other phlox varieties start to bloom. I will discuss a different phlox variety in the summer 2022 Central Region Horticulture Hints, so stay tuned!

Dr. Sara Shields
Louisiana Master Gardener State Coordinator
Central Region Horticulture Coordinator


How to Handle a Bee Kill Complaint


Establishing apiaries and keeping honeybee hives has become quite popular in recent years. One potential issue that could be encountered is losing honeybees after mosquito treatments are administered. To get more information on the matter, I reached out to Allen Fabre, Louisiana state apiarist. Fabre said beekeepers who suspect that a mosquito treatment has caused a bee kill should file a report with the Louisiana Department of Agriculture and Forestry.

A bee box set on cinder blocks by the edge of the woods.
A beehive sits along the edge of a wooded area. Photo by Keith Hawkins

Once reported, the LDAF will begin an investigation. To contact LDAF regarding a bee kill, call its toll-free number at 1-866-927-2476. Dead bees need to be collected as quickly as possible after a kill is detected, as doing so will assist with the test phase of the investigation. Additionally, beekeepers should ensure the hive is registered with the LDAF, along will the U.S. Department of Agriculture through its Emergency Assistance for Livestock, Honey Bees, and Farm-Raised Fish (ELAP) program. If you have any beekeeping questions, please contact Keith Hawkins at 318-264-2448 or KHawkins@agcenter.lsu.edu.

Keith Hawkins
Agriculture and Natural Resources Agent
Forestry Agent
Beauregard Parish


A small circular planter with two types of plants. One is a trailing, cascading vine. The other is a plant with bright purple flowers located in the center of the pot.

Get Creative With a Colorful Container Garden


You don’t need a large yard or a lot of space to create a beautiful garden. You can create beautiful planters or containers that fit any space with limitless plant combinations that bring beauty and joy to wherever you call home.

There are plenty of options to choose from when it comes to the size, shape and color of containers and planters — hanging baskets, window boxes, small and large containers for combination plantings, single plant containers and clusters of pots. Your options for the plants themselves are plentiful and diverse, too.

To create a beautiful container design, begin by choosing a container that suits your spatial needs. Most garden centers, retail nurseries and online shopping venues offer many types.

Next, choose the plants and arrange them in a design of your choosing. Keep them looking good until you want to change the design.

One of the great advantages is that you can change these out. Year after year, you can play with the plant combinations, colors, textures and themes.

A combination planter typically has what is known as a filler, a thriller and a spiller. If you haven’t heard these terms yet, let me explain them to you.

The thriller is the plant that is main attraction of your container planting. It will be the focal point of your design. Choose a plant that has some height and a striking flower form or color.

The filler is just as the name suggests. Use these plants to fill in areas to create a fuller look in the arrangement. Fillers are medium-sized plants, typically in a mounded form, that make up the bulk of the plant material in the container. You can choose just one type of plant for focal impact, or you can choose several different plant types of similar sizes.

Spiller plants are the trailing, cascading plants that flow over the sides of the containers and complete the arrangement.

When choosing fillers and spillers, a good rule of thumb is to use an odd number of plants — three, five, and seven and so on.

Symmetry brings a good balance to beginning designs. Although it is not required to have an equal number of similar or identical plants on each side of the focal point, it does bring a visual balance to the arrangement.

Be sure you bring different textures into the container planting and design. Add fine-, medium- and coarse-leaved plants. Use tall pieces that bring height for the focal point; shorter, mounding species en masse; and low-growing spiller plants to soften the edges of the container planting.

Lastly, use proportional sizes to match the container. For large containers, use larger plants; use smaller plants in small containers. The rule of thumb is that the tallest plant should not be taller than 1 to 2 times the height of the container.

Now is the fun part: picking the plants. Be sure that you use season-appropriate plants. For example, if you are creating a design for the summer, make sure you are using heat-tolerant, warm-season annuals and perennials.

Most trees and shrubs will be fine throughout the seasons, but be sure to use evergreen selections unless you plan to rotate them out with the seasons as you do with your annuals and perennials.

A metal rectangular planter planted with a variety of plants.
You can use interesting container for an artistic flair.
A large planter filled with ornamental kale and violas are the outside of the planter and yellow and purple flowering types of snapdragons in the center.
Ornamental kale snapdragons and sorbet violas make a dazzling container plant display.

Here are a few suggestions of Louisiana Super Plants for each category for medium-sized containers.

Thriller plants: Suncredible yellow sunflower, Flamethrower coleus series, Fireworks pennisetum, Senorita Rosalita cleome, Intenz Classic celosia, Flutterby Tutti Frutti buddleia, Camelot foxglove series, Diamonds Blue delphinium, Jolt and Amazon dianthus series.

Filler plants: Beacon impatiens series, Babywing begonia series, Serena and Serenita Raspberry angelonia, Mesa gaillardia series, Butterfly and Lucky Star pentas series, Sorbet viola series, compact varieties in the Sunpatiens impatiens series, Kauai torenia series.

Spiller plants: Mini Vista Indigo and Vista Bubblegum in the Supertunia petunia series, Homestead Purple verbena, lemon sedum.

Heather Kirk-Ballard, Ph.D.
Consumer Horticulture Specialist

Checklist for March, April, May


A basket full of purple egg plants with white verigation.
Eggplants.

March

  1. In the vegetable garden: Work compost and a preplant complete fertilizer, such as 13-13-13, at seven to 21 days before planting or laying mulch cloth. In south Louisiana plant beans, cantaloupes, collard greens, sweet corn, eggplants, herbs, mustard greens, okra, Southern peas, peppers, pumpkins, summer squash, tomatoes and watermelons. North Louisiana should wait until the beginning of April.
  2. In the lawn: Make your first mowing at a low setting and remove grass clippings. Continue to treat cool-season annual weeds in the lawn. Let your lawns begin to green up before you start fertilizing lawns this month after March 15 in south Louisiana and after April 1 for north Louisiana.
  3. In the landscape beds: Continue to enjoy your cool-season bedding plants that were planted in fall. They will have another outstanding display of color this early spring before it is time to replace them with warm-season bedding plants around the beginning of May.
  4. Trees and shrubs: Spring is a great time to plant new trees and shrubs. Consider size, fall foliage change, flower interests and whether you want evergreen or deciduous trees or shrubs when selecting new plants. Apply dormant oils to control scales, whiteflies and other sucking insects on trees and shrubs that may be affected. Fertilize this month if you missed it in February. Begin your preventative rose spray program in early March. Alternate fungicides to control blackspot and powdery mildew. Treat in the early morning or late evening every week. Copper is a great organic alternative to other traditional fungicides.
  5. Fruit: Apply fertilizer to fruiting trees that were not fertilized in winter now at the recommended rate. Recommended 8-8-8 fertilizer rates:
    • Blackberry – Half of a pound per plant.
    • Blueberry – Fertilize with 2 ounces per year of growth up to 1 ½ pounds.
    • Fig – 1 pound per year of 8-8-8 up to 10 pounds.
    • Citrus, peaches and plums – 1 to 1 ½ pounds per year of tree age up to a maximum of 8 pounds.
A flowerbed with tall, heat-shaped, white and green veriegated caladiums standing over some short dark green and purplish ornamental plants.
Caladiums.

April

  1. In the vegetable garden: Apply pine straw mulch to prevent weeds in the vegetable garden. The last week of April is a good time to side-dress vegetables planted in late March with ammonium nitrate, ammonium sulfate, calcium nitrate or potassium nitrate. Be sure to apply several inches away from the base of the plant and water in immediately to prevent burning. Stake tomatoes when the first flower clusters to prevent fruit from touching the ground and to help prevent fruit rot.
  2. In the lawn: Fungal diseases are common this time of year. Keep an eye out for large patch and gray leaf spot. St. Augustinegrass is susceptible and centipedegrass is more resistant. Use fungicides containing maneb, myclobutanil, PCNB, propiconazole, thiophanatemethy or triadimefon every 10 days as the fungus persists. Control cool-season annual weeds, such as bedstraw, chickweed and henbit, from producing seeds that will be a headache next winter if not taken care of now
  3. In the landscape beds: You can begin planting warm-season annuals, perennials and caladium bulbs this month. Thin border plants and clumping ground covers, such as monkey grass, liriope and hostas, this month. Use a 2-inch mulch layer on newly planted landscape beds to conserve moisture and to control weeds.
  4. Trees and shrubs: Prune spring-flowering shrubs, such as azaleas, camellias, viburnum and spireas, after they have finished flowering. Fertilize after pruning. Powdery mildew can be a problem on the foliage of ornamentals. Control with fungicides containing one of the following active ingredients: azoxystrobin, copper sulfate, myclobutanil, trifloxystrobin or triforine.
  5. Fruit: Thin fruit on your fruit trees this month. Thinning fruit improves the size and quality of the remaining fruit and can help reduce the spread of diseases.
Several limbs in covered in long dark leaves and bunches of light orange loquat fruits.
Loquats.

May

  1. In the vegetable garden: Now is a critical time to scout vegetable plants for immature stink bugs and leaf-footed bugs. If you see them spray soon. When they turn into adults, they are much more difficult to control. Continue to plant warm-season vegetables.
  2. In the lawn: Be on the lookout for weeds. If weeds are present, you can apply a lawn weed killer labeled for use on your lawn. Early weed control before going into hot summer months is essential for the best turfgrass vigor. If your weeds are under control, you can encourage vigorous turfgrass growth by aerifying your lawn. Plug removal is the best method to provide air to roots. If you fertilized in March, you may go ahead and fertilize again late this month. Lay sod or sprig your lawn this month and throughout the summer, if needed. Trees and shrubs: Mulch trees. Prune ever-blooming roses back by one-third of their height to encourage a vigorous fall bloom.
  3. In the landscape beds: Watering can be laborious in extended droughts in summertime. Consider installing a microirrigation system. Home installation kits and timers are homeowner friendly and readily available online and in stores. Be sure to buy a timer with a rain delay for days with rain. Next month is National Pollinator Month. Plant perennials, such as coreopsis, daylily, Echinacea, gaillardia, gerbera daisy, gaura, milkweeds, Louisiana phlox, passion vine, cardinal flower, sunflowers, bee balm, Mexican sage, verbena, rudbeckia, coral honeysuckle, rose mallow and irises.
  4. Trees and shrubs: This is a good time to prune spring-blooming shrubs now through no later than July to encourage new growth. Be careful not to prune summer-blooming shrubs, such as hydrangeas, butterfly bush and crape myrtles. Azalea lacebugs can be a problem in late spring and into summer. Look for white mottling or spots on the tops of leaves and dark brown insects on the undersides of leaves. Use acephate or malathion to control and be sure to cover the undersides of leaves to control the insects that are found there.
  5. Fruits: Bird netting may be necessary for fruit trees and shrubs this month. It is harvesting time for mayhaws, loquat, mulberry, peach, sweet orange, blackberries and blueberries this month.

Heather Kirk-Ballard, Ph.D.
Consumer Horticulture Specialist

Spring Vegetable Tips


If there is ever a time to be outside in Louisiana, it’s in the short-lived spring season we get. I recommend getting into the vegetable garden as early as possible. January and February are wet and cold. As soon as that garden dries in March, get going before it gets hot. The heat will come in a week, a month or, if we are lucky, in two months … in Louisiana you never know.
Two wood framed, triangular garden beds surrounded by pea gravel and filled with young snap bean and tomato plants.
Snap beans and tomatoes.

Steps to success

  1. Remove weeds and insect- and disease-infested plants from the fall garden.
  2. Work the soil. Loosely till or spade your garden area.
  3. Apply fertilizer or aged manures. A key to achieving heavy vegetable harvests is using adequate fertilizer. For example, most mixed gardens (all warm-season crops combined into one area) require a medium rate of fertilizer. There are hundreds of fertilizers to choose from. To keep the recommendation simple, I would apply one-half pound to 1 pound of 13-13-13 for every 10 linear feet of row in your garden space. That rate is assuming your rows are no wider that 48 inches. That is about 1 to 2 cups of 13-13-13.
  4. Water that fertilizer in!
  5. Plant!!! In south Louisiana plant in early-to-mid-March. In central and northern Louisiana plant April 1 or in late March if we are warm.
  6. Water your newly planted seeds and plants within one hour of planting. Keep the ground moist, not saturated, throughout the life of the garden.
A closeup of a pale yellow okra flower with dark purple center growing on stalk next to an okra pod.
Okra flower and pod.

Vegetables to Plant in March

Direct-plant snap beans, Swiss chard, radish, lettuce, collards, mustards, turnips, cabbage, broccoli and sweet corn seeds. Plant tomatoes, peppers and eggplant transplants. Plant cantaloupes, squash, cucumbers and watermelons well after danger of frost is over. This is usually after March 15 in south Louisiana and closer to April 1 in north Louisiana.

... and in April

Plant snap beans, butter beans, radishes, collards, cucumbers, eggplants, cantaloupes, okra, Southern peas (field peas), peanuts, pumpkins, winter squash, summer squash, sweet corn, sweet potatoes (late April), tomatoes (transplants), peppers (transplants) and watermelons.

... and in May

Most spring vegetables can be planted in May, since the soil has warmed and danger of frost has passed. Plant sweet potatoes (transplants), heat-tolerant tomatoes (Sun Master, Sun leaper, Florida 91, Phoenix, Bella Rosa, for example), okra, Southern peas, pumpkins, peanuts, sweet corn, watermelons, cucumbers, butter beans, squash, cantaloupe, collards and eggplants (transplants). Snap beans, butter beans, sweet corn, tomatoes (except heat-tolerant varieties) and peppers (transplants) should be planted in the early days of May to prevent poor fruit set because of high temperatures.

Enjoy the Garden,

Kathryn “Kiki” Fontenot, Ph.D.
Vegetable Gardening Specialist

Lawn Weed Control


Herbicides can be effective tools for reducing weeds in your yard, but the best way to manage weeds is to grow a thick, healthy lawn. Lawns that are managed properly are lush and healthy, with few weed problems.
A short, wide growing plant called blue eyed grass growing in turfgrass.
Blue eyed grass is an iris that often infests lawns in the early spring.
A plant with three lobed leaves with red fruit growing in turfgrass. There are pine needles scattered over the top of the weed.
Indian mock strawberry infests thin lawns.
Close up of a small plant emerging from the soil. A dime is put next to the seedling to show scale.
Crabgrass emerges in early February in south Lousiana.
A large patch of weeds called spotted burclover growing in turfgrass. Each leaf has three lobes with brown spots on a green leaf.
Spotted burclover is a common weed seen early in the spring.

Pre-emergence herbicides

Weed preventer or pre-emergence herbicides can be helpful in preventing the emergence of several summer annual grasses and broadleaf weeds. Pre-emergence herbicides may be applied safely in late winter to early spring to all established southern lawns. Most pre-emergence products for home lawns are granular and should be applied with drop or broadcast spreaders and “watered in” soon after application. These types of herbicides kill weeds as they germinate, so application timing is extremely important. You must apply before the weeds, such as crabgrass, germinate. Also, these pre-emergence herbicides that you are applying to prevent summer weeds will not kill any existing winter weeds. Residents in the New Orleans area and southernmost areas of the state should apply pre-emergence herbicides in late January or early February and then follow up with another application in mid-April. From Alexandria to Baton Rouge, residents should apply around Feb. 10, with a follow-up application in late April. If you live in north Louisiana, try to get these herbicides applied in late February, with a follow-up application by early May. Some pre-emergence herbicide trade names to look for are Scotts Halts, Barricade and Hi-Yield Crabgrass Preventer with Dimension. Consult product labels concerning rates and application techniques. When it comes to the successful use of pre-emergence herbicides, going a little early with your applications is better than applying too late. Winters over the last few years have been nearly nonexistent. Lack of cold weather has caused an earlier emergence of summer weeds. Let’s get those pre-emergence herbicides out on time.

Post-emergence herbicides

Post-emergence herbicides are used to kill weeds that already have emerged in the lawn. Winter broadleaf weeds usually are prevalent in the late winter to early spring throughout the state. MSM Turf (metsulfuron) and Celsius (theincarbazone-methyl + dicamba + iodosulfuron) are two highly effective broadleaf killing herbicides that have consistently performed well in LSU AgCenter evaluations on winter broadleaves. MSM is effective on wild onion, false garlic and blue-eyed grass (an iris), as well as most winter broadleaves. These are low-use-rate herbicides, especially MSM. Follow the product labels very carefully so that lawns and trees are not injured. Do not use Celsius on carpetgrass. More widely available broadleaf weed killers include “trimec type” herbicides formulated with the active ingredients 2,4-D; dicamba; and mecoprop. Some examples of trade names to look for with these active ingredients include Trimec Southern, Ortho Weed B Gon for Southern Lawns, and Ferti-lome Weed Free Zone. Product manufacturers will often recommend a follow-up spray two or three weeks after the first application. Broadleaf weed killers such as these are widely available and can be used on most southern grasses. Injury can occur, however, when using them on St. Augustinegrass and centipedegrass as the weather gets warmer in late spring. Atrazine is an herbicide that is effective on winter broadleaves and also controls annual bluegrass, especially when applied before the annual bluegrass flowers. Most garden centers have a good supply of atrazine on their shelves. Weed and feed products labeled for St. Augustinegrass and centipedegrass contain atrazine as their active ingredient. However, liquid atrazine sprayed on weeds in the yard has worked better in LSU AgCenter trials than atrazine weed-and-feed products impregnated on a fertilizer granule.

What about weed-and-feed products?

Weed-and-feed herbicides can be used at the times recommended for the first fertilizer application of the year. Apply weed-and-feed in the New Orleans area from mid-to-late March. For north Louisiana, early-to-mid-April is the time. Just be aware that applying weed-and-feed too early (late February to early March) may encourage outbreaks of large patch disease. Clean your sprayers thoroughly with an ammonia solution if the same sprayer is used for applying insecticides or fungicides on landscape plants. It is best to buy a sprayer specifically dedicated for weed killers, however, to avoid accidental injury to desirable plants. As always, be sure to read and follow product label recommendations before using any pesticide.

Fertilizing the lawn

Lawns vary in the amount of fertilizer required during the growing season. See the table below for information regarding the number and timings of fertilizer applications recommended for lawn species grown in Louisiana. Bermudagrass and St. Augustinegrass require the most fertilizer compared to other lawn grasses. Centipedegrass and zoysia only require one to two applications of fertilizer per year.

Lawn

Number of fertilizer applications/year

Recommended months

Bermudagrass

3

March/April, June, August (optional September)

Centipedegrass

1 to 1.5

April and possibly June at ½ fertilizer rate

St. Augustinegrass

2 to 3

April, June, August

Zoysia

2

April and July


Which fertilizer should I use during the growing season?

A spring application of weed and feed could serve as your first fertilizer application. For future applications during the growing season, consider using 3:1:2 or 4:1:2 ratios of nitrogen, phosphorus and potassium (N-P-K) as a guide for the analysis of fertilizers to choose for the lawn. For example, a fertilizer with an analysis of 21-7-14 is a fertilizer with a 3:1:2 ratio. You would be better off getting your soil tested. Soil tests would be most helpful to determine exactly what nutrients are needed to make your lawn beautiful. Contact your parish extension office concerning soil sampling your yard today.

Ron Strahan, Ph.D.
Weed Scientist and Turfgrass Specialist

Exobasidium Leaf Gall


Leaf gall of camellias and azaleas is a fungal disease favored by extended periods of cool, wet weather during spring. This is primarily a leaf disease, but occasionally it may occur on stems, flowers and seed pods. There are mainly two species of the Exobasidium fungus that cause this disease: Exobasidium vaccinii on azaleas and E. camelliae on camellias. Symptoms of leaf galls start appearing soon after the plants finish flowering. Leaves are distorted and become thickened with a fleshy or leatherlike texture (Figures 1 and 2). Galls tend to be pale green, pink or white (Figure 3) in the beginning, but as they develop, they become white and powdery. The white powder material is spores of the fungus, which readily disperse via air currents and by splashing water. As the galls get older, they shrivel up, dry out and turn brown and hard (Figure 4). Older galls fall to the ground, where they survive and may serve as a source of inoculum for the next spring’s susceptible growth.
A camellia branch with three white galls on the end of the branch.
Figure 1: A leaf gall on a camellia. Photo by Raj Singh.
Three groups of camellia leaves showing varying levels of color. Some are green, pink and brown.
Figure 3: Camellia galls show color variations. Photo by Raj Singh.
Two groups of azalea leaves laying flat on a white table. There are several protruding green galls on the leaves.
Figure 2: A leaf gall on an azalea. Photo by Raj Singh.
Close up of light brown distorted foliage.
Figure 4: An older mature gall turns brown on an azalea. Photo by Raj Singh.
Management of leaf galls is achieved primarily by adopting good cultural practices. Proper pruning and discarding of galled leaves is very important in reducing the spread of the disease. Cut galled leaves a couple of inches below the symptoms. Before discarding them, put them in zippered plastic bags. Remove and destroy affected leaves with galls that have fallen on the ground. Improve air circulation by selective thinning of the canopy of established plantings to promote rapid drying of foliage and maintain adequate spacing when establishing new plantings to avoid creating favorable conditions for disease development. Fungicides may help avoid infection when applied beginning at bud break. Repeated applications may be required every 10 days as long as the conducive weather conditions persist for disease development. For fungicide selection, please consult your local LSU AgCenter extension agent. For more information on leaf galls of azalea and camellia, please contact Raj Singh at 225-578-4562 or email rsingh@agcenter.lsu.edu.

Raj Singh, Ph.D.
Associate Professor
Director, Plant Diagnostic Center

4/18/2022 7:17:29 PM
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