Water Conservation for Lawns

By Clint Waltz, Ph.D. – University of Georgia Turfgrass Specialist

Turfgrass Spring Blog #4: 2020 Edition

All living things need water to survive, albeit a different amount for different organisms. For plants, supplemental water from irrigation is sometimes needed between natural rainfall events. Fortunately, turfgrass is a fairly robust plant that needs relatively little water for survival.

Many factors influence the amount and frequency of water needed for turfgrass within a home lawn. Soil type, type of grass, fertility level, frequency of rain, temperature, wind, and humidity all affect the amount of water needed. A high-level fertilization and hot, windy days tend to increase the demand for water, while low level fertilization and cool, cloudy days tend to decrease the demand for water.

One way of conditioning the turfgrass to need less supplemental irrigation or, to remain green between periodic summer rain showers is to tolerate some moisture stress. An observable characteristic of moisture stress in turfgrass is wilt. Wilt is a physiological defense mechanism of the turfgrass plant and allowing some moisture stress actually triggers the plant to initiate rooting, allowing the turfgrass to explore a greater soil volume for water reserves.

Before watering, look for visual symptoms of water stress, such as gray color, leaf cupping/curling, or footprints remaining on the lawn after it has been walked across. Observing some moisture stress within the lawn prior to applying irrigation can be good and improve the sustainability of the grass. Daily irrigation of turfgrass produces short roots incapable of tolerating periodic drought stress. Most established turfgrasses in Georgia only need 1.0 inch of water per week. Irrigation should be applied to supplement rainfall.

Apply enough water to wet the soil to a depth of 5 to 7 inches. Do not apply water until runoff occurs. If water is being applied faster than the soil can absorb it, turn the irrigation off and allow the existing moisture to move into the soil, then apply the remaining irrigation to achieve 1.0 inch.

Pay attention to the weather. Reduce the amount you water when it is raining or cloudy. Avoid irrigation schedules that apply more water than the turf may need. Prior to sunrise is the best time to water because of less wind and lower temperature. Research indicates water loss at night through evaporation may be 50 percent less than during midday irrigation.

Employing some best management practices (BMPs) like tolerating some wilt, allowing water to move into the soil, and not watering during the heat of the day can conserve water and maintain a healthy, attractive lawn.

Wet Weather Brings Out Mushrooms in Landscapes

Written by Carole Knight

Mushrooms are the visible structures of the unseen fungi growing in our landscapes. Think of mushrooms as the flowers and fruits of the fungi world. The mushrooms these fungi produce may cause a concern depending on where they are growing. Mushrooms and other fungal growths can be unsightly and are a concern since some may be toxic to children. They can be found growing in mulch, turf and landscape beds.

There are many types of mushrooms and other types of fungal growth including puffballsstinkhorns and others. Slime molds, though not a fungus, can appear as a slimy, oily or powdery growth on lawns, mulches or wood.

Unfortunately, it is almost impossible to prevent mushrooms and similar organisms from growing. Many fungi get their energy from decomposing dead organic matter. They are actually a part of the natural recycling process. There are no chemicals that effectively kill all the fungi that cause mushrooms. You can remove the mushroom, but you must remove the fungus to keep the mushrooms from returning. To remove the fungus, you will need to remove the organic matter upon which it is growing.

There are several possible sources of food for fungi.

  • Buried wood, roots or other organic matter. Dig up and remove the source.
  • Thatch under lawns. De-thatching and aerating the lawn may reduce mushrooms.
  • Mulch, especially mulch that is too thick. (Greater than 3 to 4 inches in depth).
  • Piles of leaves, logs and limbs. Remove them if you need to discourage mushroom growth.

Even if you remove the food source, the mushrooms may still continue to grow. Removing the food should help to some extent. Mulches can be removed, properly composted and used again.

Some mulches are more prone to producing mushrooms and other fungal growth. Proper mulch selection, application and care can reduce mushroom problems.

  • Bark chips from mature, old pine or cypress trees decay more slowly and are less prone to mushroom problems than chips from other types of trees. However, this is only true of chips from old, mature trees. Chips from young pine or cypress trees do not have this advantage.
  • Wood or bark mulches from hardwood trees can be more prone to fungal problems than bark mulches from old pine or cypress trees. Composting these mulches before use will help reduce the chance of producing mushrooms.
  • Mulches from bark or wood products should be composted for at least 6 months before being used as mulch. Add a nitrogen source to the mulch and keep the mulch moist and turned during composting
  • Do not allow mulches to get dry. This leads to an increase in fungal activity. Then when the mulch gets wet again, mushrooms appear. Apply mulches 2 inches deep and wet the mulch well at application. Keep the mulch moist but not overly wet.
  • Finer textured wood or bark mulches can be more prone to problems. Use coarser textured mulches and/or apply mulches in a thinner layer.

Mushrooms that grow at the base of trees (also called conks) are usually an indication that the interior of the tree is decaying. This can indicate that a tree is at risk to fall. If you see mushrooms (or conks) attached to tree limbs or roots, contact a certified arborist to evaluate the tree to see if has become a hazard.

Another fungal problem we see in mulch piles involves hydrophobic fungi. When mulch is applied too deeply or is piled up in areas, the mulch can be infested by these fungi that waterproof the mulch. Water will then no longer able to penetrate the mulch and the plant roots can dry out and die – even though the plants are being watered. This is especially a problem with woody mulches that are applied too deeply. Dig into affected mulches and you will notice that they are dusty dry. To prevent problems, do not apply these mulches more than 2 inches deep.

In addition, mulch piled against the base of trees can lead to tree damage and death. Pull mulches slightly away from the trunks of all trees and shrubs.

Once you begin seeing mushrooms, it may be best to just ignore or remove the mushrooms you can see and wait for the fungus to quit producing more mushrooms. This can take a while depending on the fungus, weather, etc. These fungal fruiting structures are often short-lived but interesting to watch. Try to ‘enjoy’ your landscape oddity until it runs its course.

 

Things to Do in the Garden in April

From Trellis Blog – Apr 8, 2020 | Written by 

WOODY ORNAMENTALS

  • Plant container-grown trees and shrubs
  • Last chance to plant balled-and-burlapped trees and shrubs (may no longer be available in your area)
  • Fertilize actively growing trees, shrubs, and ground covers
  • Prune conifers that are in the candle stage, broadleaf evergreens, and overgrown shrubs
  • Prune out any storm damage or dead limbs
  • Prune spring-blooming shrubs, like forsythia and azaleas, after they finish blooming
  • Mulch planting beds for weed control and moisture conservation
  • Control emerged weeds by hand or with herbicides (follow label directions)
  • Scout for diseases on trees and shrubs (azalea leaf gall, azalea petal blight, dogwood anthracnose (sometimes seen in the north part of the state), fireblight, cedar apple rust, powdery mildew, entomosporium leaf spot, black spot on roses, botrytis), but be sure to get a diagnosis and Extension recommendation before attempting to treat
  • Scout for insects on trees and shrubs (aphids, fall webworm, bagworms, dogwood borers, Eastern tent caterpillar, lace bugs, leaf miners, mealy bugs, thrips, and scales)

HERBACEOUS PLANTS

  • Plant summer-flowering bulbs, such as dahlias and gladiolus
  • Plant summer annuals according to your frost-free date (click here if you need to check)
  • Fertilize actively growing perennials and annuals
  • Consider replacing cool-season annuals late this month
  • Plant perennials
  • Plant annual herbs
  • Sow warm-season annual seeds in garden beds
  • Deadhead any spent flower blossoms
  • Scout for insects and diseases
  • Hand-weed for weed control
  • Mulch planting beds for weed control and moisture conservation
  • Fight the urge to cut back daffodil and any other spring-blooming bulb foliage (allow it to die naturally)

VEGETABLE GARDENS

  • Harvest cool-season spring crops (lettuce, chard, broccoli, peas)
  • Prepare soil for planting
  • Sow warm-season vegetable seeds (beans, squash, corn)
  • Plant warm-season transplants (tomatoes, peppers, eggplants)
  • Water transplants and seedlings, as needed
  • Hand-weed and cultivate as needed for weed control; click here for other options
  • Mulch planting beds for weed control and moisture conservation

TURF

  • Warm season turf grasses
    • Establishment of new turf, in the southern part of the state
    • Fertilization begins, based on soil test results, when soil temperatures at the 4-inch depth are consistently 65F and rising
    • Core aeration, in the southern part of the state
    • Begin planning for any renovation efforts
    • Scout for weeds. Since spring green-up is when warm-season grasses are most susceptible to herbicide injury, the mower can serve as a weed control option. If possible, mow regularly.
    • Scout for fungal diseases on turf (brown patch, dollar spot). A single fungicide application can protect the grass for four weeks. It is still early spring and a second fungicide application will likely be warranted.
  • Cool season turf grass
    • Fertilize cool-season grasses, like tall fescue and bentgrass, and grow as many roots as possible to prepare the grass for the upcoming summer heat stress.
    • Mid-month, post-emergent weed control for summer broadleaf weeds
    • Scout for fungal diseases on turf (brown patch, dollar spot, pythium blight, melting out)
    • Scout for insects (cutworms)

Warm-season grasses are beginning to transition into active growth. All the rainfall this winter has resulted in wet soils which are generally slower to warm as water is a buffer of heat.

About sdorn – Sheri is the State Coordinator for the Georgia Master Gardener Extension Volunteer Program and Extension Specialist for Consumer Ornamentals. When she is not traveling about the state of Georgia admiring the work of Georgia Master Gardener Extension Volunteers, she spends time in her own (real and virtual) gardens. Many thanks to Extension Specialists Bodie Pennisi, Clint Waltz, Elizabeth Little, Lisa Ames, and Bob Westerfield for contributing to this post!

Beware the Caterpillar Invasion

By NG Turf

This time of year it’s important to keep an eye out for two pests that often invade Georgia lawns. Both fall armyworms and also webworms are voracious caterpillars that can infiltrate in large numbers and damage your grass. Armed with information about how to find and annihilate them, you can keep your lawn healthy and beautiful.

Fall Armyworms 

As their name suggests, fall armyworms usually begin their rampage in early fall, but they may show up as early as July or August, feeding on our lush grassy lawns. Some sightings have already been reported this year, and because the striped caterpillars appear in large numbers, they can cause major damage in short order.

A pest for more than a century in the Southeast, the adult moths migrate each spring from Florida, where they overwinter in the mild climate. Each moth lays a few dozen to a few hundred eggs along the way as they move northward, building populations exponentially throughout the summer months. They reach most areas of Georgia by early fall and continue to reproduce—and eat our grass—until the first frost.

 

Damage
Armyworms harm virtually all turf grasses by chewing the plant tissue and creating ugly webpatterns in the leaves. The armyworm larvae strip foliage in one area of the lawn and move, usually all together, to the next source of food. Moving en masse like an army earned these destructive critters their military designation.

Damage varies in severity depending on the type of grass and the overall health of the grass prior to the infestationArmyworm damage rarely kills a lawn on its own, but it can significantly weaken your grass, making it far more susceptible to failure from drought and disease.

 

Win the War
Watch for birds clustered in a particular area of your lawn, often an early indication your yard has been invaded by armyworms. The caterpillars are dark in color with several light stripes down the length of the body and an inverted “Y” at the head. Young armyworms measure ½ to ¾ inch long, reaching 1-1/2 inches before burrowing into the soil for the pupa stage. They emerge two weeks later as adult moths, laying eggs to begin the cycle again.

If the worst happens and armyworms do march into your lawn and flowerbeds, treating with insecticide is your best defenseThe University of Georgia extension office recommends Bt insecticides, which are nontoxic to humans and eradicate caterpillars without harming beneficial insects in your yard. Several brands are readily available at home and garden centers.

 

Sod Webworms
Another dastardly caterpillar that feeds on Georgia lawns this time of year is the sod webworm. The adults appear as small gray or brown moths, which scatter eggs as they fly around the yard. Once hatched, the caterpillars chew on the tender grass blades, creating notched, ragged edgesSod webworms prefer newly established lawns, and they attack many grass varieties, including Bermuda, ZoysiaCentipede, and St. Augustine.

A major infestation can wipe out a lawn in a matter of days, so if you notice irregular brown patches in your otherwise green yard, try a soap flush in the affected area to confirmAdd two or three tablespoons of liquid dish soap to a gallon of water and spread with a watering can over a small 3-foot by 3-foot section in the affected area. If webworms are present, the soap solution will force the caterpillars to the surface of the lawn.

Look for caterpillars up to ¾ inch, covered in fine hairs with a dark head. Their bodies vary in color from light pink or green to a yellow brown. Treat the infested areas with Bt insecticide in the early evening, when the caterpillars begin to feed.

If you have additional questions about pest infestations or unidentified damage to your grass, give us a call at 706-800-4010.

 

Spring Turfgrass Report

We’ve received several calls and emails recently expressing concern about poor turfgrass green-up conditions. We reached out to UGA Extension Specialist, Dr. Clint Waltz, for his opinion:

“Aeration and patience would be suggested. Over the past 7 to 10 days environmental conditions have finally become favorable for growth of warm-season species. Considering April 2018 was the coldest April since 1997 , delayed green-up is not a surprise. Looking at the forecast for the next 7 to 10 days, growth of warm-season grasses should be expected and now is a good time to consider aeration to stimulate stolons and rhizomes to initiate new growth.

I am aware of NCSU Dr. Grady Miller’s observations and comments regarding cold temperature damage in North Carolina. For lawns in Georgia, I have not observed or been notified (e.g. email, text, etc.) of similar widespread cold related injury. Even in coastal areas that had abnormal snowfall this past winter, St. Augustinegrass and centipedegrass are recovering, albeit slow. Relative to the previous 16 years I have been at UGA, I would consider the 2018 spring green-up in the Atlanta /North Georgia area as “normal”.

Disease (e.g. Large Patch) is common during spring green-up, especially for zoysiagrass, centipedegrass, and St. Augustinegrass. The cooler temperatures and wet conditions of March and April may have exacerbated incidences of disease this spring but disease is not “cold damage”.”

Dr. Waltz will continue to observe turfgrass the next few weeks and provide updates.

Contact Dr. Waltz @ cwaltz@uga.edu

Pest Alert: February Monitoring for Granulate Ambrosia Beetle

Granulate ambrosia beetle, Xylosandrus crassiusculus (Mot.) [Previously known as the Asian ambrosia beetle]

Introduction: Granulate ambrosia beetle (Fig. 1) is a serious pest of woody trees and shrubs in Georgia. These tiny beetles were first detected in South Carolina in the 1970’s and have spread across the southeastern US.

Host plants: Woody ornamental nursery plants and fruit trees are commonly affected. In spring or even in late winter (around mid-February), a large number of beetles can emerge and attack tree species, especially when they are young. Some highly susceptible tree species include Styrax, dogwood, redbud, maple, ornamental cherry, Japanese maple, crepe myrtle, pecan, peach, plum, persimmon, golden rain tree, sweet gum, Shumard oak, Chinese elm, magnolia, fig, and azalea.

Biology: The female beetles land on the bark of woody trees. Then, they bore through the soft wood and vascular tissues (xylem vessels and phloem) of the tree. They settle in the heartwood and begin making galleries. Eggs are laid in these galleries. Adults introduce a symbiotic fungi into the galleries as a food source for the developing larvae. Click here to read more.

How to Reduce Worm Castings In Your Lawn

Question: I’m having a bad problem with worm castings in my lawn. The turf is turning a lumpy, muddy mess. What can I do?

Of the more than 200 species of earthworms in North America, the common night crawler (Lumbricus terrestris) is most likely to be causing your problem. They are a dominant species in temperate regions and play a big role in the breakdown of organic matter and the development of soil.

Night crawlers produce deep vertical underground burrows and feed on organic matter mainly on the soil surface. As they excavate their burrows, these worms consume mineral soil and litter. They excrete their fecal matter, or casts, in mounds on the soil surface. Researchers estimate that earthworms carry 20 to 25 tons of soil per acre up to the surface each year. Click here to read more

Landscape conifers still suffering drought stress despite recent rains

Although Georgia has received rainfall over the past few weeks, most of the state is still in a drought. The rain has improved the situation, but whether the rainfall will continue is uncertain.

Many plants have sustained damage and died as a result of the continued dry conditions in the fall. Much of the state received little or no rain from early August until December. Read more

Aerification: Restoring Turfgrass Carbohydrate Reserves

Dr. Clint Waltz, Extension Turfgrass Specialist with the University of Georgia, reports that hot temperatures and low rainfall in the fall of 2016 likely sent warm-season turfgrasses into winter dormancy with depleted carbohydrate reserves. During “normal” circumstances warm-season turfgrasses accumulate and store carbohydrates from late summer through early fall.  Read more

Mosquito Control Treatments From Lawn Care and Pest Control Companies Are a Must to Help Halt the Spread of the Zika Virus

To date, there have been recorded cases of the Zika virus in all states except Alaska and Wyoming. While most cases are travel related, there have been 43 natively contracted cases reported in Florida. If the migration of infected Aedes species mosquitoes is not halted, that number is likely to increase, if not this season, then definitely next. Read more