Don’t Blame Pests for Dry Spots in Your Lawn

Don’t Blame Pests for Dry Spots in Your Lawn

Every time we have a dry period in spring or summer, I get those predictable calls about some mysterious pest that’s playing havoc in lawns.

 

Dry areas in lawn that show up during dry periods from imperfections in irrigations system

Dry spots in lawn. Photo credit: Larry Williams

Without realizing it, the caller usually describes a textbook example of dry spots in a lawn. And many times that’s what the problem areas are – dry spots.

 

Dry spots are the result of imperfections in an irrigation system. They are revealed during dry weather. Adequate rainfall masks the imperfections in an irrigation system.

 

Possible imperfections are many. The homeowner may easily fix some irrigation system problems while other problems may require the expertise of a licensed irrigation contractor. There may be too few sprinkler heads for adequate coverage, insufficient pressure to operate each zone, incorrect choice of nozzles or wrongly mixing rotors with spray heads on the same zone. The cause for dry spots may be as simple as a maladjusted spray head, a broken spray head, a plugged nozzle, a tree or shrub blocking the water, grass that has grown over a pop-up spray head, etc.

Regardless of the cause, there are a couple of simple tests that can help confirm that the problem areas are to be blamed on lack of sufficient water vs. a mysterious pest.

First, check the affected areas by taking a soil sample in the root zone. Use a soil probe or shovel to remove a core of soil to a depth of 6 to 8 inches. Visually inspect and feel the soil sample for moisture. Do the same test in an area of the lawn that looks normal and compare the difference. It should be obvious if there is a difference in moisture between the areas tested.

The second test involves placing several empty straight-sided cans such as tuna fish cans in the affected area and several in a “normal” area of the lawn. Then let the irrigation system run long enough to collect some water in the cans. Compare the amount of water collected in the two areas. It should be obvious if there is a difference in the amount of water applied in the areas tested.

These tests are cheaper, less trouble and more environmentally friendly as compared to purchasing and applying pesticides for nonexistent pests as a result of incorrectly diagnosing the problem. If these tests do not identify the problem as lack of water, you may have a lawn pest. But don’t guess.

Occasionally inspect your irrigation system while it’s running for obvious, easily corrected problems such as a maladjusted or broken spray head. The following UF/IFAS Extension publications will help with your inspection. https://edis.ifas.ufl.edu/entity/topic/residential_sprinkler_systems

Video: Soil Moisture Sensing Helps Deliver Water as Needed to Turf

Video: Soil Moisture Sensing Helps Deliver Water as Needed to Turf

Applying the right amount of water to the lawn when the turf actually needs water is not always the easiest task for busy homeowners. UF IFAS Extension Escambia County Master Gardener Volunteer Greg Leach shares information about a soil moisture monitoring system that attaches to a home sprinkler system. This can help you apply water to the turf when it is actually needed by measuring soil moisture availability.

North Florida Lawns are Frustrating

North Florida Lawns are Frustrating

I’ll be the first to admit that North Florida lawns are frustrating. With time, most people discover this.

Why are lawns so difficult here? The answer involves a combination of factors.

We are not far enough north to benefit from the better soils. Florida is known for sandy, low fertility, low water holding capacity soils. Some areas of the country enjoy richer soils with better water and nutrient holding capacities. These better soils result in a more favorable lawn root environment with roots being more competitive and resilient.

Something else happens in more northern areas. The heavier soils and colder temperatures (sometimes resulting in the soil freezing) are natural means of inhibiting and/or controlling certain soil dwelling pests. For example, nematodes are not nearly the concern in northern lawns. Many people that move to our area have never heard of these microscopic roundworms that play havoc in our low fertility, warm, sandy soils. After a lawn has been in place for a number of years, allowing the nematode population to reach a threshold, the lawn begins to decline. And we have few legal, effective chemical control options for nematodes in Florida lawns.

Dying area in lawn due to ground pearls

Declining area in lawn due to ground pearl. Photo credit: Larry Williams

Some other soil dwelling pests that northerners don’t have to deal with include ground pearls, small scale-like insects that bother centipedegrass roots. Mole crickets are not a pest much north of Central Alabama. Years ago, a representative with the company that manufactured the once popular mole cricket insecticide Oftanol told me that in the absence of the state of Florida, they would not sell enough Oftanol to keep it on the market. Take-all Root Rot, a common soil dwelling fungus, plays havoc in our Florida lawns and it is difficult to control.

We are not far enough north to use the more trouble-free northern grasses to create a permanent lawn. These include bluegrasses, fescues and perennial ryegrass. At best, these grasses can be used to overseed our lawns during the cooler fall and winter months to create a temporary winter lawn. But they will not survive our hot, wet summers.

We are not far enough south to benefit from the lack of freezing temperatures during winter. A late freeze that occurred on April 8 a number of years ago resulted in much lawn injury. I saw lawns with seventy percent kill from this late freeze. This is something that typically does not happen in Central and South Florida.

We deal with saltwater issues, high humidity, hurricanes and tropical storms, an array of lawn insects and diseases and extremes in rainfall and temperatures.

It’s no wonder most people become dissatisfied with their lawns. Perhaps we should lower our expectations and enjoy the natural flora and fauna of our state.

Turfgrass Q & A

Turfgrass Q & A

Worm mounds in bermudagrass. Photo credit Mary Salinas, UF IFAS Extension.

The April 8 program of Gardening in the Panhandle LIVE! was focused on turfgrass, quite a popular topic in the springtime as the weather warms and turf comes out of winter dormancy. Here are some of the questions asked of our University of Florida experts and the links to resources they shared.

To start with, two sites that have comprehensive information are Your Florida Lawn: http://hort.ufl.edu/yourfloridalawn/ and Gardening Solutions: https://gardeningsolutions.ifas.ufl.edu/

Turfgrass Selection

Q. What’s the answer to “I want a lawn like I had up north”? Remotely possible?

A. You can have a nice lawn, but it is going to be different in the panhandle. Don’t expect the same grass species or maintenance.

Q. What grass species is recommended for winter overseeding, and when should the grass be sown?

A. Overseeding has its problems and generally not recommended as it shades out the warm season turf as it is coming out of dormancy in the spring. Overseeding Florida Lawns for Winter Color: https://sfyl.ifas.ufl.edu/archive/hot_topics/lawn_and_garden/overseeding_winter_lawns.shtml

Q. How well do new turfgrass varieties thrive against weeds?

A. A healthy and properly maintained lawn is your best defense against weeds and other pests. Additionally, ProVista is a new cultivar of St Augustinegrass that can tolerate glyphosate so it makes it much easier to kill weeds in the lawn. ProVista is not yet widely available in the panhandle.

Q. How do I get a lawn started?

A. Preparing to Plant a Florida Lawn: https://edis.ifas.ufl.edu/lh012

Establishing a Florida Lawn: https://edis.ifas.ufl.edu/topic_lawn_establishment

Q. Can I have a native lawn? What are some recommended alternatives to a turf lawn?

A. Opinions are divided as to whether St. Augustinegrass is native. See these links for lawn Alternatives:  https://gardeningsolutions.ifas.ufl.edu/lawns/turf-types/alternatives-to-turfgrass.html

https://gardeningsolutions.ifas.ufl.edu/mastergardener/webinars/mg-update-june2018/ffl-lawn-alternative-mg-update-june-2018-handout.pdf

Fertilizing & Weed Control

Q. How long should I wait before fertilizing new sod?

A. Wait 30-60 days before applying fertilizer. See: Homeowner Best Management Practices for the Home Lawn: https://edis.ifas.ufl.edu/ep236

Q. Basic fertilizer for most lawns if no other information is available.

A. 15-0-15

Q. Are weed and feed products effective? Can you use a Weed & Feed like Scott’s Bonus S this late in the year?

A. Weed and feed products are not recommended.

Weed & Feed, Not Foolproof: https://ocmga.wordpress.com/2013/03/11/weed-and-feed-not-foolproof-by-larry-williams-ufifas-extension-agent/

Weed Management Guide for Florida Lawns: https://edis.ifas.ufl.edu/ep141

Lawn Maintenance & Renovation

Q. My husband overwaters the lawn. Remind everyone about correct watering.

A. Homeowner Best Management Practices for the Home Lawn: https://edis.ifas.ufl.edu/ep236

Watering Your Florida Lawn: https://edis.ifas.ufl.edu/lh025

Sprinkler calibration: https://gardeningsolutions.ifas.ufl.edu/care/irrigation/calibrating-your-irrigation-system.html

Q. What to do about bare spots in St Augustine turf in shade?

A. Rough up the ground and put ½ to 1” compost and let the grass fill in or plant plugs. St. Augustinegrass for Florida Lawns: https://edis.ifas.ufl.edu/lh010

Q. When is the best time to overseed? I have a centipede lawn that’s 15-16 years old and I’m trying to bring it back to health.

A. Be sure to be following good practices and centipedegrass should not fail. Overseeding may not be the best option. Centipedegrass for Florida Lawns: https://edis.ifas.ufl.edu/lh009

Q. How do I repair lawn areas ruined by piled up Hurricane Sally debris?

A. Homeowner Best Management Practices for the Home Lawn: https://edis.ifas.ufl.edu/ep236

Q. How do I care for a zoysiagrass lawn?

A. Zoysiagrass for Florida Lawns: https://edis.ifas.ufl.edu/lh011

Q. Should I mulch or bag clippings?

A. Unless you have disease or weed seeds, mulch the clippings onto the turf so you can return the nutrients and water into the soil. Mowing Your Florida Lawn: https://gardeningsolutions.ifas.ufl.edu/lawns/lawn-care/mowing-your-florida-lawn.html

Pest Management

Q. When is the best time to put out a pre-emergence treatment to control and prevent weeds in your lawn (warm and cool season)?

A. Summer Annual Weed Control Timeline: https://sfyl.ifas.ufl.edu/media/sfylifasufledu/escambia/horticulture/Summer-Annual-Lawn-Weed-Control-Timeline.pdf

Winter Annual Weed Control Timeline: https://sfyl.ifas.ufl.edu/media/sfylifasufledu/escambia/horticulture/Winter-Annual-Lawn-Weed-Control-Timeline.pdf

Q. How do I manage chamberbitter in lawns?

A. Chamberbitter: https://hgic.clemson.edu/factsheet/chamberbitter/

Gallery, with the active ingredient isoxoben, has always been the best product to control chamberbitter. Another product, Gemini, adds prodiamine with isoxoben and also provides good control.

Q. How do you get dollar weed under control?

A. Control irrigation. Dollarweed loves lots of water so make sure you are not overwatering. See: https://edis.ifas.ufl.edu/ep389

Q. I used Image to help control Bahia in Centipede. Anything else that we can use?

A. Metsulfuron methyl, 3 applications every 21 days

Q. Which postemergence herbicide is safe and effective for reducing oxalis in a lawn?

A. Yellow Woodsorrel (Oxalis) Biology and Management in Turf: https://edis.ifas.ufl.edu/ep385

Q. What is the best non-poison weed killer?

A. If a product is a weed killer, whether it is organic or synthetic, it is a poison. Alternatives to Synthetic Herbicides for Container Plants & Homeowner Herbicide Guide: https://edis.ifas.ufl.edu/ep464 & https://edis.ifas.ufl.edu/ep575

Q. How do I treat lawn fungus?

A. First you need to determine which fungus, if any, is responsible. Key to Identification of Landscape Turfgrass Disease: https://edis.ifas.ufl.edu/lh064

Then turn your attention to Turfgrass Disease Management: https://edis.ifas.ufl.edu/lh040

Q. How do I diagnose and control mole crickets?

A. Look at this UF guide: https://edis.ifas.ufl.edu/in1021

This video shows how to do the soap flush to scout for mole crickets https://www.youtube.com/watch?v=sx_o4EMXsCo

 

 

Winter Annual Weeds, a Great Place to Hide Easter Eggs

Winter Annual Weeds, a Great Place to Hide Easter Eggs

As a boy in a small town in Georgia we had a St. Augustinegrass lawn. My dad started the lawn before I was born. That lawn was still doing fine when I left for college at age seventeen. I don’t remember weeds in the lawn during summer months. I do fondly remember winter “weeds” in that lawn.

To see clumps of winter annuals in our yard and in neighbors’ yards was a natural part of the transition from winter to spring. They added interest to what

Bluish Easter egg hidden in chickweed

Blue Easter egg hidden in chickweed. Photo credit: Larry Williams

would have been a plain palette of green. It was expected to see henbit with its square stiff stems holding up a display of small pinkish purple flowers in late winter and early spring. A clump of henbit was a great place to hide an Easter egg, especially a pink or purple one.

Wild geranium, another common winter annual, offered another good hiding place for Easter eggs with its pink to purple flowers. Large clumps of annual chickweed would nicely hide whole eggs. Green colored eggs would blend with chickweed’s green leaves.

Pink Easter egg hidden in crimson clover and hop clover mix

Pink Easter egg hidden in crimson clover & hop clover mix. Photo credit: Larry Williams

Crimson clover with its reddish flowers, hop clover and black medic with their bright yellow flowers were good hiding places for Easter eggs. Plus clovers add nitrogen back to our soils.

I never remember my dad using any weed killer, he rarely watered. The lawn was healthy and thick enough to be a deterrent to summer weeds. But during fall and winter as the lawn would naturally thin and go dormant, winter annual weeds would run their course.

I’ve heard that the sense of smell provides our strongest memories. I remember the first mowing of the season with the clean smell of chlorophyll in the spring air. It was refreshing. Once mowed and as the heat took its toll, by late April or mid-May, these winter annual weeds were gone. What was left was a green lawn to help cool the landscape as the weather warmed. The lawn was mowed high as St. Augustine should be, played on and typically not worried with.

Most people have winter weeds in their lawns that let us know spring is near. Perhaps we worry too much with these seasonal, temporary plants that may have wrongly been labeled as weeds. Besides, how long have we been doing battle with these weeds and they are still here. Most lawns have countless numbers of winter annual seeds awaiting the cooler temperatures and shorter days of early winter to begin yet another generation. By May they are gone.

Timing is Everything for Spring Lawn Fertilizing

Timing is Everything for Spring Lawn Fertilizing

Our trees and vines are flowering and lawns are starting to green up naturally, but one glance at the calendar and it is still early spring.  The last official frost date for the Florida panhandle can be into April depending on location.  We know our day time and night time temperatures are still fluctuating every other day.  We also know the stores and nurseries are stocked with shelves and pallets of fertilizer.  So the big question is when can I fertilizer my lawn?

Ryegrass

Overseeded ryegrass on a centipedegrass lawn.

My answer after years of practice is always it depends, but my non-scientific rule of thumb to homeowners is wait until you mow three weeks in a row and make sure you’re past the last frost dates for your area.  If you need to mow three weeks in a row for height, then your lawn is actively growing and most likely we are into a temperature range good for fertilizer applications.  If you apply fertilizer to a lawn that is dormant, the fertilizer will not be taken up by your roots and it can leach below the root zone wasting money while not improving the lawn and possibly causing environmental concerns.

With that said, there are some factors to consider.  We always recommend doing a soil test first.  This can be done in advance of spring.  Your test results might indicate having sufficient nutrients in the soil, so not applying would save you money and the lawn would still look good.  The soil test will also indicate what nutrients are in excess or lacking, then you can apply only the nutrients needed.

I have found that fertilizer is still very much misunderstood.  When I ask homeowners whether they consider fertilizer to be medicine or a stressor, most will answer medicine and we all know if a little medicine is good, then a bit more is better.  However, it is more accurate to think of fertilizer as a chemical stressor.  If my lawn is unhealthy, then I force my lawn to grow and it can further weaken my plants.  Think of it like this, if you’re not feeling well at night before you go to bed, should you consume one of those big energy drinks?  Not if you want to sleep and hopefully feel better in the morning.  Apply fertilizer when the lawn is ready and capable of having a positive response when spring fully arrives.

Bahia mix

Wakulla County Extension office mixed species turf.

Here are some items you should know before you fertilize the lawn.  Fertilizers used in Florida should have a license number that begins with F followed by a series of numbers.  It is important to check your fertilizers before you apply.  You need to know what type of turfgrass you have in your lawn.   We have a lot of bahiagrass and centipedegrass lawns in the panhandle.  Each will require a different regiment.  You are only allowed to apply one pound of nitrogen per 1,000 square feet per application and you should never apply more than the recommended rate.  I always refer to a childhood fable “The Tortoise and the Hare” when thinking about plant health.  Slow and steady makes for a better lawn in the long run.  This means you need to measure your lawn, understand how to calculate the nitrogen and then apply correctly with the right equipment and spreader patterns.  We also recommend very little phosphorus (the middle number on the fertilizer bag 15-0-15) for Florida lawns.  Our soils are usually sufficient and this is another item your soil test results will confirm.

Remember, your local Extension office is always here to help especially making sure you treat the lawn right.  Think before you apply because your long-term goal is improving the lawn quality.

 

The Florida Fertilizer Label (https://edis.ifas.ufl.edu/ss170) and General Recommendations for Fertilization of Turfgrasses on Florida Soils (https://edis.ifas.ufl.edu/lh014). T. W. Shaddox, assistant professor; UF/IFAS Fort Lauderdale Research and Education Center, Ft. Lauderdale, FL 33314

Homeowner Best Management Practices for the Home Lawn (https://edis.ifas.ufl.edu/ep236).  Laurie E. Trenholm, professor, Extension turfgrass specialist, Environmental Horticulture Department; UF/IFAS Extension, Gainesville, FL 32611.

Bahiagrass for Florida Lawns (https://edis.ifas.ufl.edu/lh006).  L. E. Trenholm, professor, turfgrass specialist, Department of Environmental Horticulture; J. B. Unruh, professor, turfgrass specialist, UF/IFAS West Florida Research and Education Center; and J. L. Cisar, retired professor, turfgrass specialist, UF/IFAS Ft. Lauderdale REC; UF/IFAS Extension, Gainesville, FL 32611.

Centipedegrass for Florida Lawns (https://edis.ifas.ufl.edu/lh009).  J. B. Unruh, professor, turfgrass specialist, UF/IFAS West Florida Research and Education Center; L. E. Trenholm, associate professor, turfgrass specialist, Environmental Horticulture Department; and J. L. Cisar, professor, turfgrass specialist, UF/IFAS Ft. Lauderdale REC; UF/IFAS Extension, Gainesville, FL 32611.