Horticulture Hints for Louisiana - Winter 2022

Sara Shields, Strahan, Ronald E., Hawkins, Keith, Timmerman, Anna, Polozola, Michael, Abdi, Damon, Simoneaux, Mariah, Fontenot, Kathryn, Fields, Jeb S., Mathews, Marcie, Kirk-Ballard, Heather

LSU AgCenter, Research, Extension, Teaching. Horticulture Hints for Louisiana. Winter 2022.

Upcoming Events


Central

Dean Lee Virtual Field Tour
This tour plus more horticulture videos can be found on the Dean Lee YouTube channel at https://bit.ly/DeanLeeYouTube and the Central Region Horticulture web page.

Visit our Central Region Horticulture website for more information on a range of horticulture topics.


Southeast

Spring Garden Tour
April 22, 2023
1 p.m. to 5 p.m.

St. Francisville Town Hall
11936 Ferdinand St.
St. Francisville, LA 70775
lsuagcenter.com/springgardentour

Close up photo of Dianthus blooms in white, as well as light, medium, and dark pink colors.
Dianthus Amazon Rose Magic blooming at Dean Lee Research & Extension Center. Photograph by Brandi Woolam.
Greetings! We hope the Winter 2022 edition of Horticulture Hints contains information you can use to keep your lawn, gardens, and landscape looking great during this time of year. Our spotlight for this quarter is on dianthus planted at the Dean Lee Research and Extension Center. There are two different dianthus series on the Louisiana Super Plant list – Amazon (2010) and Jolt (2019). Plants in both series require full sun and will flower from late February or March through late May or early June. As the name suggests, the Amazon series grows taller and wider than the Jolt series. Amazon dianthus grows 18-36” tall and 10-16” wide, and the plants should be spaced 12-16” apart when installed in the landscape, whereas the Jolt series grows 16-24” tall and 12-14” wide. While fall planting is best, you can usually find these plants on retail nursery benches throughout the winter months, as the plants are hardy into the teens. Three colors of the Amazon series of Dianthus are included on the Louisiana Super Plant list: Neon Purple, Neon Cherry, and Rose Magic. If you are interested in the Jolt series, look for Cherry, Pink, and Pink Magic. When planting, work 3-4” inches of organic matter, such as compost, into the upper 6-8” of soil. Adding mulch after planting can help increase water retention by the plants. And to keep the plants looking their best, be sure to deadhead after blooming. Please join us as we continue to expand and strengthen our horticulture efforts throughout the Central Region. If you have any questions on these initiatives, please contact your local LSU AgCenter Extension Office.

Sara Shields, Ph.D.
Louisiana Master Gardener State Coordinator
Central Region Horticulture Coordinator

Master Gardeners in the Central Region


The Master Gardeners Program has been active and growing in the Central Region. For example, three of the Master Gardeners associations in the area have created their own Facebook pages to help gardeners and homeowners with questions about horticulture. They are:


These Facebook pages share horticultural articles from the LSU AgCenter in their respective communities, and visitors to these sites can share their questions and learn about plants and landscapes.

The Grant LaSalle Master Gardener Association celebrated Louisiana Arbor Day at the Grant Walker Educational Center on Jan. 28. The Master Gardeners had a short ceremony and planted two donated Chinese pistache trees.

In Beauregard Parish, the Master Gardeners participated in the local National Night Out on Aug. 2. The outreach event by the Beauregard Sheriff’s Office had and the theme of “Mayberry Comes to DeRidder.” The Master Gardeners were able to meet people and answer their gardening questions. They also signed up possible students for the next Master Gardener class in January 2023. The group also had two plant sales and a booth at the Beauregard Parish Fair.

Photograph showing an NNO with Merlyn Giltner.
Master Gardener Merlyn Giltner with Barney Fife impersonator, Rik Roberts. Photo by Keith Hawkins, LSU AgCenter.

Photograph showing a group of arborists that participated in the Arbor Day.
A newspaper clipping celebrating Arbor Day at Camp Grant Walker. Photo by The Jena Times.

The Cenla Master Gardeners were extremely active with landscape designs and improvements at Forts Randolph and Buhlow State Historic Site, Alexandria Zoological Park, Kent Plantation House and demonstration gardens at the Rapides Extension office.

Photograph showing Linda and Matt Deshotel working in a flower bed at the zoo.
Linda and Matt Deshotel volunteering at the Alexandria Zoo.

Photograph showing a group of Master Gardeners that participated in the CENLA class.
New Master Gardener graduates include, back row, from left, Donna Rico, Vickie Miller, Donna Beaubouef, Judy Palin, Katherine Negrotto, D.D. Lamartiniere, Jan LeMoine and Sam Scalfano; and kneeling, Gerald LaVergne, and Master Gardener coordinators, Keith Hawkins and Mike Polozola. Photo by Bob Hines, Cenla Master Gardener.

The Master Gardeners of the Central Region were successful in recruiting new people to several Master Gardener classes. For the first time in about a decade, the Avoyelles Extension office in Mansura hosted a class with fourteen members. Master Gardener class participants receive horticultural training in weeds, insects, plant diseases, turf, vegetables, ornamental plants and other related topics.

The Grant LaSalle Master Gardeners were very successful in building a new class and had 16 people enrolled in the November class at Grant Walker Educational Center.

Keith Hawkins
Area Horticulture Agent

Consider Adding Carnivores to Your Houseplant Collection


Series of small pink and yellow leaves with sticky substance to attract and trap insects.
Butterworts growing in small container. Photograph by Michael Polozola.

If you like cultivating traditional houseplants, you may be interested in broadening your horizons by adding a few carnivorous plants to your houseplant collection. Carnivorous plants come in many forms. To be officially classified as a carnivorous plant it must have a mechanism to both capture and digest prey.

Oddly enough there are some plants that lack the second component of this but still capture insects. Those plants are not officially considered carnivorous since they lack the digestion component. Instead, they rely on bacteria breaking down what is captured to eventually get some nutritional benefit from their hunt. One common plant that falls under this category is petunias. Insects can get trapped in their hairy/sticky leaves and die. One of the primary reasons these plants not quite reach the level to carnivory is that it is mainly a defense mechanism and not an attempt to get nutrients.

A common characteristic of most carnivorous plants is that they tend to be native to nutrient poor environments. Instead of hunting for mineral nutrients in the soil with their roots, carnivorous plants developed specialized plant structures to hunt for nutrients by trapping organisms in the air, soil, and water. The most common adaptation that plants use to trap organisms is modified leaves. A great diversity of structures come from modified leaves including pitchers, mechanical traps, and sticky traps.

Pitcher structures in carnivorous plants come in a great variety of shapes and structures. One of my favorites is Cephalotus, Australian or Albany pitcher plant, that creates low growing mounds of cute small pitchers. There are several pitcher-based carnivorous plants native to the United States with Sarracenia, trumpet pitchers, being our most prominent local one. They form long narrow tubular pitchers that come out of the ground in clumps. There are many color combinations available but the one you are most likely to encounter in the wild here is the pale or yellow trumpet.

Sticky traps in carnivorous plants are what Drosera, commonly called sundews, use to capture their prey. Sundews have hair like structures on their leaves that exude a sticky dew. When an insect gets bogged down by the dew the hairs will slowly move to encircle the prey and prevent its escape. Under the right light the dew is quite striking which is how they got their common name the sundew. Plants that have this adaptation are found across the globe and we have several native selections in Louisiana. They are often low growing and discrete so they can be hard to notice unless you are looking for them. A common place to find some in our environment is active cemeteries and graveyards. Regular grass cutting, a minimized fertility regiment and disturbed soils in those places create a patchy turf where they can thrive.

Another common carnivorous plant that relies on the sticky trap method is Pinguicula or butterworts. They look similar to succulents except their leaves are moist and sticky. They are efficient at catching fungus gnats which make them a great companion for house plants. While they are prevalent to many climates, some of the most ornamental selections originate in Mexico. The most common colors are green, but they can be found in pink, red, and purple. Proportions can also be variable ranging from coin to plate size.

Close up of bright pink and neon green leaves, with long sensors around edge.
Close up of several Venus flytrap plants growing in small container. Photograph by Michael Polozola.

The most famous carnivorous plant structure is mechanical traps. This is what Venus flytraps, Dionaea species, use to catch its prey. Their traps have trigger hairs on them to detect movement. When they sense enough activity in their snare, they quickly close. After closing, it makes a determination to see if what it caught was big enough to bother with. If it was a false alarm or not big enough, it opens back up. If it decides it has a meal, it will start to digest its catch. Venus flytraps come in many forms and colors as well. There has been a great interest in the plant recently so many new red and unique trap shapes are becoming more common. It is important to note that some of these new selections have lost some of their hunting skills and may require a little assistance.

Close up of a dozen or more small maroon pitchers on a pitcher plant.
Container with maroon-colored pitchers on Pitcher Plant.Photograph by Michael Polozola.

If you want to try growing carnivorous plants at home, make sure to do some research and prep work beforehand. For those of you that have a tendency to over water plants, carnivorous plants may be a good fit since most selections prefer to be moist most of the time. You do have to be careful though as some are prone to root rots or have a reduced water demand while they are dormant. Another common mistake is not enough light, make sure you have a very sunny spot or supplement with plant lights indoors for the best results. For house plants, butterworts and sundews are great choices while trumpet pitchers and Venus flytraps excel in a bog garden outdoors. If you are interested in learning more about carnivorous plants, check out our Central Region Horticulture website. A link to the website can be found on page one, in the left-hand column.

Michael Polozola, Ph.D.
Central Region Horticulture Agent

Louisiana Native Plants for Winter Interest


The winter landscape can be bleak and drab, with long stretches of dried lawn and barren trees. Sure, we have several options for color that come in the way of cool-season bedding plants such as pansies, snapdragons, petunias and ornamental cabbages. But what about something different with a visual appeal that is sure to attract the eye in the dead of winter? Several native plants provide winter interest in the landscape in the form of berries, interesting bark, dried seed heads or attractive foliage. Here are some native plant recommendations for striking winter appeal.

Photograph showing a dried hydrangea flower in the winter in detail.
Dried hydrangea flower in the winter.

Oakleaf hydrangea is a native flowering deciduous shrub occurring naturally in central and southeast Louisiana. This shrub offers year-round appeal with its panicle flowers in summer, orange-burgundy foliage in the fall and attractive bark in the winter. The retained dried flowers add visual winter interest. Oakleaf hydrangea prefers morning sun with afternoon shade and moist, well-drained soil. Varieties include the Gatsby Series, Snow Queen and Ruby Slippers.

Adam’s needle (Yucca filamentosa) is an evergreen succulent flowering plant native to northern and southeast Louisiana. Its sage-colored, dagger-like leaves provide a striking contrast against the backdrop of winter. The curly threaded leaf margins and dried flower stalks and seed heads add to the appeal. One popular variety is Color Guard, with its creamy variegated leaves and compact size making it a perfect addition to rock gardens or mass plantings. Gulf Coast yucca (Yucca louisianensis) is native to mostly the western parishes but is similar in growth habit. Rattlesnake master (Eryngium yuccifolium) is native to much of Louisiana and is similar in form to yucca with its pale green needle-like leaves and compact rosette habit. The greenish-white, thistle-like flower heads and pointed bracts atop the stalks are what set this species apart. With maturity, the flower globes will develop a bluish hue. The dried seed heads are favored by songbirds in the winter and will reseed readily. Purple coneflower is a desirable alternative to avoid volunteering.

Partridge berry (Mitchella repens) is an evergreen groundcover native to most Louisiana parishes. It is in the same family as Virginia buttonweed, (Rubiaceae) but holds all the appeal and none of the dread. It has similar flowers to Virginia buttonweed but are fragrant, appearing May through October. The flowers transform to singular scarlet berries that persist through winter. The evergreen foliage is attractive and similar in appearance to creeping fig. It prefers woodland settings of part to full shade, and moist conditions and is available through most native plant nurseries.

Pink muhly grass (Muhlenbergia capillaris) is a newly named Louisiana Super Plant and for good reason. It has not only winter but year-round appeal. The flower plumes transform from pink to hay-colored after first frost. The dried plumes add texture and movement to the winter landscape. This native warm-season perennial grass is low maintenance, performing best in full sun to partial shade and well-drained soil. Muhly grass is native to most parishes and widely available in nurseries as an ornamental grass.

Marcie Wilson
Northeast Region Area Horticulture Agent

Smashing Pumpkins: Turning Fall Decorations Into Next Year’s Compost


Leaving fall and entering winter where cooler temperatures prevail, it is easy to be afraid of changes, but a landscape is built around views. Time makes days shorter and temperatures colder, and now you have pumpkins to use. Those pumpkins may have served their purpose as jack-o’-lanterns on your front step, providing a seasonal aesthetic benefit, but as you begin to take them down, pause for a moment. Reflect on the frost-covered windowsills and consider crowded landfills.

Pumpkin fragments from smashing and breaking apart a pumpkin.
Smashing pumpkins into smaller pieces will help the composting process.

Consider using these grungy Halloween and Thanksgiving holdovers as part of a management plan for the landscape. The remainders of a pumpkin can be used as a component in a rich, fertile compost material, recycling nutrients back into your landscape. But be warned. If improper composting procedures are used, then some frustrating issues may arise.

Pumpkin remains are laden with seeds, and these seeds will maintain viability if not properly composted. If this occurs, then your landscape beds might turn into pumpkin patches after you spread your compost. To avoid the likelihood of this happening, a thorough hot composting practice should be used.

The first step in bidding farewell to your fall decoration is to break the pumpkin into smaller pieces, smashing it up to create more surface area. The greater amount of surface area, the faster and more efficient the composting process will be. The microbial community will be able to develop faster and degrade the pumpkin remains more rapidly and thoroughly when it is fragmented. The smaller the fragments, the better it is for composting.

With your pumpkin pieces ready to go, it is important to use a hot composting process. Add pumpkin remains to a compost pile or compost container and maintain a higher temperature of roughly 130 F. This will help to limit the number of viable seeds and pathogens and create a healthier compost.

So the next time the neighbors ask you why the sound of smashing pumpkins is so loud, they won’t be asking you to turn down the music. In fact, they are probably just interested in ways to get the most out of composting this season.

Damon E. Abdi, Ph.D.
Assistant Professor
Extension Specialist, Hammond Research Station

Jeb S. Fields, Ph.D.
Assistant Professor
Assistant Research Coordinator, Hammond Research Station

Prune Trees and Shrubs with Purpose


Nearly all the trees and shrubs in our home landscape will need pruning at some point during their lifetime. In urban environments pruning is necessary to keep limbs from coming in contact with power lines and buildings. After storms many trees need pruning to remove damaged and twisted branches. Pruning to create a more attractive or useful plant can also be accomplished. No matter what your issue or desire may be, always remember to prune with purpose.

Deciduous trees, which lose their leaves seasonally, should be pruned during the winter months while the plant is dormant and branch structure is most visible. When pruning a tree, try to work with the tree’s natural growth pattern. If you are unsure where to begin, start with the three D’s removing any dead, damaged or diseased branches first. Next, evaluate where branches are and how they are growing. If a branch is too long or growing in the wrong direction, prune it back to a side branch growing in a more appropriate direction or remove it entirely.

Drawing of a tree trunk and branch that is to be cut. Drawing contains labels descriping the anatomical parts of the tree as well as indicate the where to cut and at what angle.
A drawing of a tree indicating where to prune and at what angle.

Summer-flowering trees and shrubs, such as althea, crape myrtle, oleander and vitex, can also be pruned this time of year. Crape myrtles are frequently pruned incorrectly using a technique called topping. Topping results in a crew cut appearance, often referred to as crape murder. Crape myrtles that are repeatedly pruned in this manner are left structurally weak and more susceptible to some disease issues.

Determining the best time to prune citrus trees is a common concern of many south Louisiana homeowners. Citrus trees should be pruned in February, once the coldest part of the winter has typically passed but prior to the tree putting out any new growth or flowers. Pruning is beneficial to citrus trees and can improve overall tree health. Remove branches that are crossing, rubbing or too low to the ground. Aim to open up the tree’s canopy, increasing light penetration and air circulation.

When you are making your pruning cuts, cut outside of the branch collar at a 45-degree angle (Figure 1 ). Pruning too close or too far from the trunk or remaining branch can lead to future problems. A cut too close to the tree can create a larger wound than necessary. A cut too far can leave a branch stub susceptible to rot and disease.

Select the correct tool when pruning to minimize damage to the tree. Small branches can usually be removed using a pair of sharp loppers or pruning shears. Larger branches should be removed using a hand saw. A pole is useful for reaching limbs that are higher within the tree’s canopy. A professional arborist may be required for any major pruning. Never put yourself if a precarious position in order to make a cut.

Mariah Simoneaux
Horticulture Extension Agent
Ascension and Assumption parishes

Checklist for December, January, February


seasons-icons-solid.jpg thumbnail

December

  1. Garden gift ideas for the holidays: Purchase memberships to local botanical gardens or arboretums for the holidays or gift cards to retail garden centers. Of course, don’t forget plants and gardening gadgets and tools.
  2. In the vegetable garden: Bunching green onions and shallots should be harvested by digging up the clumps. You may replant a smaller piece to continue producing. You can plant beets, Brussels sprouts, cabbage, carrots, celery, cabbage, leeks, lettuce, radishes, shallots, spinach, Swiss chard and turnips.
  3. In the lawn: This is a great time to sharpen mower blades and take care of any mower or weed trimmer maintenance before storing for the winter. Rake and keep fallen leaves of deciduous plants and trees to use as a mulch or to compost.
  4. In the landscape beds: Protect the roots and rhizomes of tropical plants by spreading a 4-to-6-inch layer of mulch around the base of the plant. Plant tulip and hyacinth bulbs at the end of the month.
  5. Trees and shrubs: Prune freeze damaged portions of tropical herbaceous foliage plants, such as gingers and philodendrons. Heavily mulch cold sensitive trees and plants and cover them in extended periods of below freezing weather.
  6. Fruits: Heavily mulch citrus trees to protect them from freezing temperatures. Cover young, tender citrus trees and utilize heat lamps during extended freezes.

January

The New Year is a great time to set new goals. Start a new year in your garden journal. Look back on what did and did not work last year. Set new goals for your garden this year. If you’ve never kept a gardening journal, it’s a great time to start!
  1. In the vegetable garden: Mid-January to late February is time to start Irish potatoes for mid-spring harvest. You can direct seed beets, carrots, peas and radishes now. If your vegetables need a boost of fertilizer, side-dress with a teaspoon of complete fertilizer placed a couple of inches from the base of the plant.
  2. In the lawn: Large patch disease can come and go throughout the winter if the weather is mild. Treatment with fungicides containing myclobutanil, propiconazole, pyraclostrobin and triticonazole or azoxystrobin will reduce the spread. Damage can slow spring green-up, and diseased areas will remain bare until warmer spring weather conditions help turfgrass recover. Diseased areas become more prone to weed infestations in the spring, so stay on top of weed suppression.
  3. In the landscape beds: Deadhead to keep cool-season annuals blooming longer. Keep winter weeds in check by applying 2 to 4 inches of mulch. It’s not too late to transplant cool-season annuals and perennials for color in the garden this month.
  4. Trees and shrubs: Prune ever-blooming roses. This is a good time to plant trees and relocate established trees and shrubs that you want moved elsewhere in the yard. Be sure to go out a foot or more out from the trunk of an established tree or shrub to get an adequate root ball. Water newly transplanted trees well to help encourage new root growth.
  5. Fruit: Collect dormant wood from fruit trees such as figs for propagation this month. Fertilize citrus at the end of January through early February and apply 1 to 1 1/2 pounds of 8-8-8 or 13-13-13 per year.

February

February is National Bird-Feeding Month. By providing a diverse selection of plants in your garden, you can provide more food for caterpillars and, in turn, for birds and other wildlife. Additionally, we can place bird feeders, birdbaths and birdhouses in our gardens that benefit our feathered friends. Consider planting something for the birds this month for a food supply next year. Visit https://www.audubon.org/native-plants and enter your ZIP code to find plant species that support birds in your area.
  1. In the vegetable garden: Direct-seed beets, turnips, mustard, parsley, radishes, lettuce, snap beans and Irish potatoes. Corn planted late this month will have fewer earworms. Broccoli, cabbage, cauliflower, chard, kale and lettuce can still be transplanted successively every two weeks to ensure a steady harvest. Control weeds with pre-emergent herbicides such as Dual and Treflan. To control grass weeds, use Poast or other herbicides with the active ingredient sethoxydim.
  2. In the lawn: Stop sticker weed, clover and annual bluegrass before it gets out of hand with a broadleaf herbicide such as atrazine. For the best results combine 2,4-D plus dicamba plus mecoprop (trimec-type herbicides) to control winter broadleaf weeds on the same lawns that were sprayed with atrazine. Metsulfuron (MSM) works well on lawn sticker weed (burweed) and is highly effective on clovers and false garlic.
  3. In the landscape beds: Trim groundcovers, such as liriope, monkey grass and Asian jasmine, to about 4 inches before new growth emerges. Fertilize Louisiana iris and calla lilies and other fall-planted, spring-flowering bulbs and cool-season annuals with a slow-release granular fertilizer. Prune repeat-blooming roses.
  4. Trees and shrubs: Plant trees that benefit birds. Some trees to consider are beech, elm, holly, sycamore, bald cypress, cedar, magnolias, tulip trees, maples and oaks of all types. Some native shrubs to consider are American beautyberry, arrowwood, buttonbush, blueberry and spicebush. Prune your roses on or around Valentine’s Day and begin a preventative spray program alternating fungicides for blackspot and powdery mildew. Fertilize spring-blooming trees and shrubs.
  5. Fruit: It is time to fertilize fruit trees and shrubs including apples, peaches, citrus, figs, blueberries and blackberries. Dormant cuttings can be taken from 1-year-old growth fig trees and stored at 40 degrees Fahrenheit for a month or so before rooting in moist media.

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

Photo of a small stand of bald cypress along the edge of a pond.
Bald cypress bordering a pond.

Take a Break From Holiday Madness and Get Into the Garden


Make time this holiday season for yourself, but instead of spending extra money on a dinner out, pedicures or going to the movies, spend time in the garden. Gardening clears your mind, gives you a break from visitors and provides much needed fresh air and exercise. Below are a few things to do and plant this winter season.
A variety of lettuce heads and leaves grown in a garden.
Lettuce heads grown in a garden.

December

  • If it is not too wet, make rows in your garden for the spring season. This might sound early, but the weather is quite unpredictable in the winter and often can be wet. It is never a good idea to work wet soil.
  • Plant onions and shallot sets. October was the month to plant onion seeds, but south Louisiana gardeners can plant sets now. North Louisiana gardeners should wait until late January. Onion varieties we recommend include Red Burgundy, Southern Belle, Candy, Georgia Boy, Miss Megan and Texas Grano 1015Y. If possible, select thin onion sets since thicker sets tend to bolt in really cold weather.
  • Scout for insects. Likely culprits are aphids on lettuce, kale and chard and worms in broccoli, cabbage and cauliflower. Only use insecticides when you see the insect, not as a preventative. Insecticides, such as horticulture oil, insecticidal soap and bifenthrin products (Ortho Bug B-Gon Max), work great for aphid control. Insecticides that kill worms and loopers include Sevin, Bt (Dipel) and spinosad.
  • Order spring vegetable seed if you want first pick of great varieties. If you wait too long, it will be too late to start your spring transplants.

January

  • Onion sets can be planted starting mid-December in south Louisiana and late-January in north Louisiana. You may continue planting through early March.
  • During the second half of the month, transplant broccoli, cabbage, cauliflower and lettuce, and direct seed Irish potatoes into the garden. As potatoes begin to sprout and grow, pull soil from the sides of the row towards the plant each week. Doing this prevents tubers from pushing upwards and coming into direct contact with sunlight. Sunlight will cause green skins which is a sign that solanine is forming. Eating potatoes with green skins can make you sick. Make sure your tubers are covered as they grow.
  • Vegetable growers in south Louisiana should start their tomato, eggplant and pepper transplants mid-January. North Louisiana vegetable growers should wait until the end of January or the beginning of February. It takes between eight and 10 weeks to germinate and grow into a decent sized seedling for the garden. Keep seedlings in a warm and bright area. One week prior to transplanting, move the seedlings outside to harden off.

February

  • If it is not too wet, make rows in your garden for the spring season. This might sound early, but the weather is quite unpredictable in the winter and often can be wet. It is never a good idea to work wet soil.
  • Plant onions and shallot sets. October was the month to plant onion seeds, but south Louisiana gardeners can plant sets now. North Louisiana gardeners should wait until late January. Onion varieties we recommend include Red Burgundy, Southern Belle, Candy, Georgia Boy, Miss Megan and Texas Grano 1015Y. If possible, select thin onion sets since thicker sets tend to bolt in really cold weather.
  • Scout for insects. Likely culprits are aphids on lettuce, kale and chard and worms in broccoli, cabbage and cauliflower. Only use insecticides when you see the insect, not as a preventative. Insecticides, such as horticulture oil, insecticidal soap and bifenthrin products (Ortho Bug B-Gon Max), work great for aphid control. Insecticides that kill worms and loopers include Sevin, Bt (Dipel) and spinosad.
  • Order spring vegetable seed if you want first pick of great varieties. If you wait too long, it will be too late to start your spring transplants.

Happy gardening!

Kathryn “Kiki” Fontenot, Ph.D.
Vegetable Gardening Specialist
LSU AgCenter School of Plant,
Environmental and Soil Sciences

Winter Turfgrass Management


The dormant season

Most lawns should be dormant or at least close to this stage by Christmas. Because lawns are not actively growing, fertilizer applications are not needed during the winter. Most lawn fertilization for growth should have stopped on home lawns by late summer (late August to very early September for St. Augustinegrass and centipedegrass).

Nitrogen fertilizer on dormant to semi-dormant St. Augustinegrass, centipedegrass and zoysiagrass lawns can lead to increased brown patch and winter kill. Also, nitrogen applications during this time have a greater potential for leaching or movement into non-target areas.

Soil sampling and pH adjustments

I’m a big believer in soil testing. If your lawn did not perform well last growing season or you just want to get a quick check on soil pH, get the soil tested. Winter is an excellent time to collect soil samples and submit them for analysis.

Samples should be a composite of soil collected from 3 to 4 inches deep at various places around the lawn. Mix well and reduce the sample to about a pint of soil and take it to the LSU AgCenter Extension office in your parish or to a participating garden center. Make sure to specify the type of grass you are growing on the soil test form.

Soil samples submitted to the LSU AgCenter result in a wealth of information concerning the overall fertility of your soil. If results of the soil test indicate the soil pH is too acidic, lime will be prescribed in the soil test recommendations. Sulfur may be prescribed for soils that are too alkaline. Winter is the best time to apply lime or sulfur so that it can be activated by the growing season next spring and summer. The correct soil pH is extremely important and has everything to do with nutrient availability and fertilizer performance.

Turf establishment

Postpone any permanent warm season turfgrass seeding until next spring. Soil and air temperatures will be too cold for germination and growth.

Sod, such as St. Augustinegrass and centipedegrass can be laid during winter and established successfully during the spring. But remember to maintain good moisture to prevent the sod from dying. Establishment of sod is easiest, however, when sodding is delayed until the middle of spring, well after spring green-up.

Large patch disease
(formerly brown patch)

Large patch disease can come and go throughout the winter if the weather is mild. Treatment with fungicides containing myclobutanil, propiconazole, pyraclostrobin and triticonazole and azoxystrobin will reduce the spread of large patch. Damage from large patch will slow spring green-up, and diseased areas will remain unsightly until warmer spring weather conditions help with turfgrass recovery. These diseased areas become more prone to weed infestations.

Photograph showing a bluegrass seedhead in detail.
Annual bluegrass seedhead.

Winter weed management

Broadleaf weeds, such as clover, lawn burweed (sticker weed) and annual bluegrass infesting St. Augustinegrass, centipedegrass, zoysiagrass and bermudagrass can be suppressed with two applications of atrazine herbicide – one in the late fall followed by one in the winter. The window for these atrazine applications is from October to early March. Herbicides containing a three-way mixture of 2,4-D plus dicamba plus mecoprop (trimec-type herbicides) can be used for winter broadleaf control on the same lawns that were sprayed with atrazine. MSM (metsulfuron) works well on lawn burweed and is highly effective on clovers and false garlic. Weed-and-feed products can be substituted as your first application of fertilizer during the early spring.

When it comes to managing lawn burweed specifically, don’t wait until the stickers show up in April to treat. It’s too late then. Spray burweed in early November with products mentioned previously. Repeat these applications in February/March.

Photograph showing catchweed bedstraw in detail.
Catchweed bedstraw.
Photograph showing lawn burweed in detail.
Lawn burweed.
Photograph showing mock strawberries in detail.
Mock Strawberry.
Photograph showing wild geranium in detail.
Wild geranium.

When should you resume fertilizing your lawn?

Lawns may show signs of green-up in southern Louisiana in late February. Do not push turfgrass growth with fertilizer at that time! Fertilizer applied too early will feed winter weeds and will result in lush turfgrass growth that is more susceptible to injury from late frosts and increased levels of large patch disease. Lawns may be fertilized in the New Orleans area by late March, but delay fertilizing central Louisiana lawns until April. Consider fertilizing lawns in north Louisiana around mid-April.

Ron Strahan, Ph.D. Associate Professor
Turfgrass Science/ Weed Science
LSU AgCenter

1/31/2023 10:01:03 PM
Rate This Article:

Have a question or comment about the information on this page?

Innovate . Educate . Improve Lives

The LSU AgCenter and the LSU College of Agriculture

Top