by Larry Williams | Jun 10, 2017
Typical ground pearl damage to lawn. Photo Credit: Larry Williams
There are numerous reasons why maintaining a North Florida lawn is challenging and ultimately frustrating.
One such reason is ground pearls.
Ground pearls, small-scale insects that bother turfgrass roots, are soil dwelling pests that are not much of a problem in northern lawns. But they are quite the problem in North Florida lawns.
Most people, having never heard of ground pearls, may blame weeds, mole crickets and a multitude of other possible causes for their lawn’s demise. But in the last two to three years, this insect seems to have become more of a problem in many of our lawns, including mine.
Unfortunately, there is no effective chemical control for ground pearls in lawns.
Ground pearls feed on roots of bermudagrass, bahiagrass, St. Augustinegrass and zoysiagrass but prefer centipedegrass. They suck juices from the roots. Their feeding eventually causes areas of the lawn to thin and die out to bare ground, especially when the grass is under stress due to drought, nutritional deficiencies, etc.
Reddish adult female ground pearl & immature “pearl” stage. Photo credit: Larry Williams
Many times, the dying areas are somewhat circular or serpentine in pattern. Sometimes the circular areas coalesce, forming larger, irregular shaped dying areas. Weeds tend to invade infested areas.
The quote below, taken from a UF/IFAS Extension publication on this insect, provides some insight into their life cycle. “Clusters of pinkish-white eggs, covered in a white waxy sac, are laid in the soil from March to June. Tiny crawlers attach to roots and cover themselves with a hard, yellowish to purple, globular shell. These “pearls” range in size from a grain of sand to about 1/16 inch. They may occur as deep as 10 inches in the soil. The adult female is 1/16 inch long, pink in color, with well-developed forelegs and claws. Adult males are rare, tiny, gnat-like insects. One generation may last from 1 to 2 years.”
It is the immature stage (nymphs), which look somewhat like tiny pearls from which they get the “ground pearl” name. In this stage, they look like tiny shiny pearls once they are uncovered and exposed to sunlight. They are less than a BB in size. They overwinter in the “pearl” stage.
The ineffectiveness of insecticides is at least partly due to the ground pearl’s ability to avoid insecticides because of being protected in the soil and because of the prolonged protective “pearl” stage of its life cycle.
Since there are currently no biological or chemical controls that work, it’s recommended to minimize lawn stress and maintain proper fertilization and irrigation to help grass tolerate the damage.
Additional information on ground pearls is available at the following UF/IFAS Extension publication “Ground Pearls”.
by Larry Williams | May 11, 2017
Adult Ladybug. Photo Credit: James Castner University of Florida
A number of summers ago, I noticed whiteflies on a confederate rose plant in my landscape. I considered using an insecticide to control the whiteflies but decided against doing so after taking a closer look. What I found was a population of ladybugs – eggs, larvae, pupae and adults.
Ladybug adults and larvae eat whiteflies, as well as other soft-bodied insects such as aphids. So, I waited to see what would happen.
At first I was seeing mostly adult whiteflies, which look like tiny white moths. Adult whiteflies mate and then lay eggs on the underside of leaves. The eggs hatch into flat translucent scale-like nymphs that suck the “juice” from the underside of the leaves.
Eventually, some of the leaves developed a black coating called sooty mold. As certain insects (primarily aphids, some scales and whiteflies) feed, they excrete plant sap that coats the leaves. Sooty mold then grows on this sugary sap. It’s not a pathogen. It just makes the leaves look ugly.
Knowing that the whiteflies would not kill the confederate rose, I was willing to tolerate the sooty mold and allow the ladybug population to build.
Allowing whiteflies to live on your plants may not always be the best option. But in order to have beneficial insects in your landscape, there must be some “bad” insects for them to eat.
Insects such as ladybugs, lacewings and praying mantises eat many pest insects. Encouraging these beneficial insects can allow you to reduce the amount of pesticides applied.
It’s important to learn to recognize the adult and immature stages of these beneficial insects. Ladybugs have larvae that look nothing like
Ladybug larva. Photo credit: Aristizabal University of Florida
the adults. Some ladybug larvae look like small orange and black alligators. Others may resemble mealybugs. Many gardeners that would never kill adult ladybugs mistake their larvae as pests and kill them with insecticides.
The following UF/IFAS Extension website will help you learn to recognize many of our beneficial insects. http://edis.ifas.ufl.edu/topic_beneficial_insects
Once you find beneficial insects in your landscape, reduce or eliminate the use of insecticides. When an insecticide is needed, use environmentally friendly options such as insecticidal soaps, horticultural oils and products that contain Bacillus thuringiensis (Bt).
Sometimes a heavy stream of water from a water hose is all that is needed to remove pest insects from plants and reduce their numbers to an acceptable population.
Remember, leaving a few pest insects is a great way to attract beneficial insects. Tolerating a minor infestation and a little plant damage will benefit the helpful insects, your pocketbook and the environment.
by Larry Williams | Apr 13, 2017
Spittlebug damage on centipedegrass. Photo credit: Larry Williams UF/IFAS
Mole crickets, chinch bugs and spittlebugs are common lawn insect pests to begin watching for this time of year.
Mole crickets can be active in lawns spring through fall, but the best window of opportunity to control them is in June and July.
Soap flushing is a technique to survey for mole crickets. Mix two ounces of liquid dishwashing soap in two gallons of water and apply with a sprinkling can to four square feet of turf in several areas where mole crickets are suspected. If an average of two to four mole crickets appear on the surface within several minutes, then a treatment is probably needed.
Chinch bugs only damage St. Augustinegrass. So if your lawngrass is something other than St. Augustine, don’t worry about this insect.
Damage from chinch bugs tends to begin in April. However, they are more likely to be active during warmer summer months through early fall in the more sunny areas of the yard, particularly if it’s dry.
Inspect a St. Augustinegrass lawn weekly during spring, summer and fall. Look for areas that quickly turn yellow and then straw brown. Part the grass at the margin of the yellowed areas and closely examine the soil surface and base of the turf for tiny insects. Immature chinch bugs are pink to red and are about the size of a pinhead. The adults are only 1/8 inch long and black with white wings.
Spittlebugs attack all turfgrass species but centipedegrass is their favorite. The first generation of adult spittlebugs is abundant in June and the peak population usually occurs in August to early September.
An early sign of spittlebug activity are masses of white, frothy spittle found in the turf. Each piece of spittle contains one immature spittle bug. Infested turf turns yellow and eventually brown. Damage resembles chinch bug injury but usually first appears in shady areas. Closer inspection reveals discolored individual grass blades with cream colored and pinkish-purple streaks running the length of individual blades. As the population builds, the ¼ inch long adults are abundant. As you walk through or mow an infested area, numerous adult spittlebugs fly short distances when disturbed. Adults are black with two orange transverse stripes across their wings.
Correct lawn management can minimize many pest problems. If a pesticide becomes necessary to control a lawn pest, be sure to follow the product’s label instructions and precautions.
by Larry Williams | Feb 25, 2017
Florida farmers produce more fresh tomatoes than any other state. Yet Florida home gardeners find it difficult to grow tomatoes. By changing a few basic practices, home gardeners can increase their chances of success.
My philosophy of growing tomatoes in Florida (mixed with science) is outlined below.
First, I choose mostly determinate varieties that have resistance to key diseases.
Most gardeners are used to growing indeterminate varieties. Farmers mostly grow determinate types. Determinate varieties are more compact and produce most of their crop at one time. You can usually harvest all the fruit in two to five pickings and then pull up the plants. Indeterminate varieties, sometimes referred to as “everbearing” tomatoes, set fruit along a vine stem that continues to grow all season.
Correct variety selection is a must for success with tomatoes in Florida.
One reason home gardeners have a difficult time growing tomatoes in Florida is because of incorrect variety selection. Most popular (indeterminate) tomato varieties lack resistance to Tomato Spotted Wilt Virus (TSWV) and bacterial wilt. These two diseases wreak havoc in home as well as commercial plantings. Amelia, a determinate variety that has TSWV resistance, has started showing up in some retail outlets. For a list of other varieties to look for, consult this publication, “Tomatoes in the Florida Garden”.
Secondly, I plant reasonably early – usually after April 1 (maybe earlier this year due to warm late winter). Tomato plants grow best when temperatures exceed a specific base temperature for a certain number of days (referred to as heat units or degree days). Tomatoes are heat-loving plants that need a long warm growing period to grow from seed to fruit. Optimum fruit set occurs within a narrow night temperature range. Tomatoes produce the largest yields of highest quality fruits when day temperatures are in the range of 80 to 85ºF and when night temperatures remain above 62 but below 72ºF.
Thirdly, I fertilize to produce a healthy, sturdy plant when the plant is young. With the first open flowers, I reduce fertilization (particularly the nitrogen) to about half the original rate. When the first fruits are about two inches in diameter, I reduce fertilization a little more. Once I harvest the first tomatoes, I further reduce the fertilizer to about ¼ the original rate or completely quit fertilizing. Many home growers fertilize tomatoes too much. This results in a big green plant with few tomatoes. This reduction in fertilization is mainly important with the amount of nitrogen being applied. The plant still benefits from adequate potassium.
There are two basic phases of growth in plants – vegetative and reproductive. When a tomato plant begins to produce flowers, it is becoming sexually mature (switching from a vegetative phase of growth to a reproductive phase of growth). Just remember that as plants mature and fruit, the demand for nitrogen decreases. Excessive nitrogen can reduce fruit set and development. Too much nitrogen keeps the plant in a vegetative phase of growth resulting in a big, overly vigorous, green plant with few to no fruit.
As heat, humidity, rains, diseases and insects increase during summer months, tomato production declines. Entire plants may begin to die. At this point, I’m thankful for any production I got. I do away with the plants and find something else to do other than grow tomatoes.
by Larry Williams | Jan 26, 2017
Live oak with immature acorns. Photo credit: Wendy VanDyke Evans, Bugwood.org.
Do you have more acorns than you know what to do with? When oaks produce loads of acorns, it sometimes is called a “mast” year. Do you remember the oak tree pollen and all those catkins that fell from oaks earlier in spring?
Catkins are the male flowers in oaks. Some people refer to them as tassels or worms. The airborne pollen from these catkins were part of the reproductive process in fertilizing the female oak flowers that ultimately resulted in all of these acorns. Oaks produce separate male and female flowers on the same tree. Female flowers in oaks are very small. You’d have to look very close to see them. Many oaks did well in their reproductive efforts this spring. Acorns are oak seeds. This entire process is part of the cycle of life.
There are theories about mast years, wildlife’s use of these acorns and what gardeners can expect next year as a result of this year’s abundant acorn crop. Timing of mast years is still a mystery. Numerous theories exist ranging from weather to geography to the life cycles of predators.
The most likely reason for high production seems to be weather-related. When oak trees have favorable weather at the time of oak flowering and good growing conditions, the mast seems to be increased.
But mast years happen irregularly, making it difficult to understand what causes a mast year. Heavy acorn production can occur twice in a row or it might be separated by several years or more. There’s no good way to predict it.
Mast years are important to wildlife, as acorns are an important food for many animal species. In low crop years, birthrate for some wildlife species, such as squirrels, will decline the following year. This also may involve increased competition for food and survival rates. The recent crop means that more young are likely to be produced by animals that forage for acorns.
Wildlife play a big role in forest regeneration. When acorns drop out of oaks, many animals help distribute these seeds. Squirrels can bury hundreds of acorns. Some of these acorns germinate and grow to become the next generation of oak trees. Some will be eaten by birds, bears, deer, rodents, including squirrels, and other wildlife. Rodents are in turn eaten by carnivores and deer browsing shapes which kinds of plants become established and survive. All those acorns have far-reaching impact on wildlife and our forests.
So, try to keep this in mind as you are fussing with all those acorns in your lawn and landscape this season.
