Environmental Horticulture — Turfgrass

What is the best fertilizer for my St. Augustinegrass lawn? How often should I fertilize it?

It is recommended that your St. Augustinegrass lawn be fertilized a minimum of twice per year (in the spring and late summer) with a complete fertilizer such as 16-4-8 or 12-4-8. If nitrogen is applied in summer, a slow release source is suggested. Summer fertilization with high rates of soluble nitrogen can increase chinch bug damage, gray leaf spot disease, and excessive rapid growth, which can contribute to thatch.

Top

Every winter my lawn turns brown, but I have noticed some lawns in my neighborhood remain green all year. What grass is this?

The permanent lawn grasses used in Florida are warm season grasses, which turn brown at the first frost. To produce a green winter lawn, you can overseed your established lawn with a cool-season grass called ryegrass. This should be planted at the end of October or early November. The seed should be sowed at a rate of 5-15 lbs./l000 sq. ft. Regular mowing, fertilizing and watering are necessary to maintain a ryegrass lawn during winter.

Top

How often should I water my grass? And when is the best time of the day to do this?

It is nearly impossible to say how many times a week a lawn should be watered since so many factors will influence this. Thus, it is best to water on an as-needed basis when the grass shows signs of stress from a lack of water. Some of those signs are:

  • The grass color will be a bluish-gray rather than a clear green.
  • Footprint impressions will remain for a long time (approximately one minute) when the grass is walked on.
  • Grass blades will fold in half.
  • Soil samples from the root zone feel dry.

A general rule for watering is to apply ¾" of water when grass shows these signs of stress which often requires two to three times per week in the summer and once every ten to fourteen days in the winter. The best time for lawn irrigation is in the early morning hours to avoid prolonging the dew period, which can encourage disease problems.

Top

I haven't been able to find St. Augustinegrass seed. Do you know where I can get it?

Current varieties of St. Augustinegrass do not produce viable seed, therefore it must be established by vegetative propagation - sprigs, plugs, or sod. See "St. Augustinegrass for Florida Lawns"

Top

What type of grass will grow in my shady lawn?

All of the turfgrasses that are grown in Florida require full sun except centipedegrass and several varieties of St. Augustinegrass: Seville, Bitterblue, Jade, and Delmar. Seville, Jade, and Delmar have a semi-dwarf growth habit while Bitterblue has a normal growth habit. However, neither will take dense shade. Maintaining as high of a mowing height as possible will encourage turf growth in moderate shade.

In densely shady areas, planting a shade loving ground cover or mulching, instead of turfgrass, is recommended.

Top

Every spring my Bahiagrass lawn develops yellow spots even though I fertilized. What causes this?

These yellow spots indicate iron deficiency in Bahiagrass. In spring, Bahiagrass grows so rapidly that it cannot keep up with its own nutritional demand for iron. It is best to make supplemental iron applications and avoid heavy fertilization or a fertilizer high in water-soluble nitrogen since this will encourage excessive growth and increased demand for iron.

Keep in mind that insects, diseases, high pH, and soil compaction can also cause yellow spots in the lawn so rule these problems out first before making a recommendation. Centipedegrass and sometimes St.Augustinegrass, also have problems with iron deficiency.

Top

When should I reseed my Bahiagrass lawn? I have had trouble getting the seed to grow.

The best time to seed is from April through June since this permits a full growing season before cold weather and takes advantage of the rainy season. Poor germination can be caused by a couple of factors: Germination of Bahiagrass seed is often slow and erratic because of a hard waxy seed coat, therefore, buy only scarified seed (seed mechanically treated to increase the germination rate). Bahiagrass must also be covered with soil and kept constantly moist in order to encourage germination.

Top

I have read about this wonderful miracle grass called Zoysiagrass. Is it as good as the advertisement says?

Due to several over-enthusiastic promotions and advertisements, the public has been misinformed on the merits of Zoysia grasses. Zoysias have advantages and disadvantages like all Florida lawngrasses. The improved Zoysias have to be propagated vegetatively and are extremely slow in becoming established. Two growing seasons may be required for coverage of the lawn when propagated by plugging or sprigging. Zoysias produce a heavy thatch, which requires periodic renovation.

Other disadvantages include slow recovery from damage; requires a reel mower; high fertility requirement; need for frequent irrigation; can be severely damaged by nematodes, hunting bilibugs, and several diseases. The University of Florida does not recommend this as a viable lawn grass in Florida except for those with ample time and financial resources to provide the intense maintenance practices required to grow desirable Zoysiagrass.

Top

I can control most of the weeds in my lawn, but I always have difficulty with grassy weeds. Any suggestions?

Weed killers that are labeled safe for grasses usually will not kill grassy weeds because their structures are too similar. A pre-emergent herbicide will prevent the germination of annual, grassy-type weeds and any other weeds that grow annually from seed. Pre-emergent weed killers are applied before weed seeds begin to germinate in early spring and/or early fall.

Top

Should I leave my grass clippings on the lawn or should I have a catch bag on my mower?

If you are mowing frequently enough, it is best to leave the clippings on the grass. By leaving the clippings on the ground they will decay and the nutrients in them will be reused by the turf. Mow often enough so that not more than 1/4 or 1/3 of the total leaf surface is removed at a given mowing.

Top

My St. Augustine lawn is spongy, and I was told this is a thatch problem. What is the best control?

A spongy lawn is normally because of loosely knit grass runners. The grass is usually growing too rapidly and producing the open growth habit. Using thatch removal techniques thins out the lawn but does not take care of the real problems.

In most instances, a spongy lawn has been over watered and over fertilized. Reducing care to a minimal schedule of watering only when needed, and feeding two to three times a year, helps to reduce the excess growth. Some gardeners apply up to an inch of builders sand or clean topsoil, to fill in between the loose runners.

Top

What is a good spray program to control lawn pests?

There was a time when gardeners sprayed every other month, March through October to control lawn pests. University of Florida studies found most lawns flourished without the frequent pesticide treatments. They also revealed many beneficial insects help control the pests. Good bugs include earwigs, spiders, and big-eyed bugs. The pesticides kill these as well.

Most gardeners scout their yards and stay alert for declining turf. Problem areas are checked for pests and sprayed as needed. Lawns also decline because of drought, diseases, nematodes and lack of sun.

Top

My lawn is about 50% crabgrass, and my spray company says it has no control. What should I do?

The post-emergence herbicide once used by the spray companies is no longer available for home lawn use. At this time of the year remove the crab grass and then add sod or plugs.

The growing crab grass can be raked out or spot-killed with a nonselective herbicide that allows replanting shortly after use. Replace the crab grass immediately with new turf. Sod and plugs grow rapidly at this time of the year and can create a new lawn before problem weeds become established.

Because your lawn was predominantly crab grass, you can expect plenty of seeds ready to grow next spring. To stop this apply a pre-emergence herbicide in late winter. Several brands are available, so apply in mid-February, and follow the instructions on the label.

Top

We would like to replace Bermuda grass with St. Augustine. How can we be successful?

Start the change to St. Augustine by eliminating the Bermuda grass. Use a nonselective weed control product like Roundup that eliminates the top growth and the roots. Apply once, and wait a few weeks. Check for signs of new shoots and treat again if necessary.

When you are sure most of the Bermuda is under control, till the soil several inches deep and rake out the debris. Rake the area smooth and add the sod. Check the sod carefully. Bermuda grass is sometimes found growing in the new turf. As the sod begins growth, stay alert for growing Bermuda grass. Even the best soil preparation techniques never eliminate the weeds. Where needed, spot-kill new invasions.

Top

I have several patches of wild Bermuda grass that are brown and appear dormant in my Bahiagrass lawn. Can I use Roundup to control the grass, and can I reseed now?

The Bermuda has to be green and growing for the Roundup to be effective. Also it may take more than one application to control most of the runners. It's best to spray once when the spring growth begins and then wait a few weeks to see if some of the dormant sprigs begin to sprout. Then you can apply Roundup again and wait a few more weeks before tilling the soil and seeding new grass.

Top

I had a shady backyard that was once Bahiagrass but is now full of dollarweed. What can I plant in the yard if I control the dollarweed?

It's a problem. When you control the weeds, it could be difficult to reestablish grass in the shady areas. If you want to try, eliminate the dollarweed with Finale, Roundup or a similar herbicide that allows re sodding or plugging after use.

Next remove the weeds when brown with a firm raking. It's best not to till near or under pine trees to avoid damaging their sensitive roots. Then install new sod or plugs of a shade tolerant St. Augustine variety, like Bitterblue, Delmar, Palmetto, and Seville.

Try to reestablish turf in a small area first to see if by the end of the spring the grass begins new growth. If it too declines, a groundcover may be better, like English ivy, mondo grass, liriope, or Asiatic jasmine.

Top

A thin-leaf weed is growing in our St. Augustine lawn and the lawns of neighbors. It's not a sedge and appears to be the same grass that grows on golf courses. Is there a control?

Your golf course grass is Bermuda. It's a tough competitor for the St. Augustine you are trying to grow as a lawn. Home gardeners do not have a selective control available now. Also it's about impossible to pull or dig out of the lawn. The best control is spot-killing with Roundup, Finale or similar product, and add new St. Augustine when the Bermuda grass declines.

Top

Portions of my lawn remain yellow even though I have applied a fertilizer. What should I do to regreen my grass?

Lawns may develop iron deficiencies during late winter and early spring. The yellowing often occurs when the turf grows in soils with a high pH. Also when the soils are cool, the iron is less likely to be available in sufficient quantities to supply the needs of the growing grass.

Giving the grass a general feeding can make the problem worse. The major nutrients in the fertilizer push growth without having adequate iron available, and the grass gets more yellow.

Use an iron-only product to renew the green. You can obtain granular or liquid formulations from your local garden center. Also have the soil acidity checked, and adjust the pH if needed.

Top

Insects damaged a portion of my lawn, and now weeds are filling the bare spots. I was told the weeds cannot be controlled by an herbicide without damaging the grass. Is this correct, and how long do I wait after treatment to plug the lawn?

Some weeds are too tough for selective herbicides. Others resemble the good grass and are not affected by the available weed control products. In these instances, the only control is to dig them out or apply a non-elective herbicide that allows replanting. Some products available at local garden centers include Finale and Roundup.

Where chemicals are applied, allow the weeds to turn brown. Then you can add plugs of turf through the old grass and weeds. It's probably best to loosen the soil as the grass is added. Stay alert to weeds growing between the plugs, and spot-treat with an herbicide or dig them out as needed.

Top

What is the name of the plant or weed that produces the sticky seed-like things that attach to socks and shoelaces? Some people call them hitchhikers.

There are several that come to mind. One is the sandbur, also called the sandspur, that is a grassy weed. The sticky portions are stiff and painful if they stick into skin.

Another, the heartleaf drymary, is common during the cooler months. The seed pods are sticky but painless. Others that might attach to the clothing include beggerweed and chickweed, which are also common in home lawns.

Top

I want to install a new St. Augustine lawn. Should I wait until spring, or can the sod be laid now? What happens if there is a hard freeze this winter?

Don't wait any longer to enjoy your new St. Augustine lawn. This grass seems to like the cooler months and grows well fall through spring. There are few pests at this time of the year, and you can control the water to prevent root-rot problems.

A severe winter could damage the grass, but it would affect most new and established lawns similarly. Even when browned, the turf almost always regrows shoots from runners close to the ground when the warmer weather returns.

Top

I have replaced some of the soil and resodded areas of my lawn that were affected by nematodes. Is special care needed to strengthen the roots and help them compete with these pests?

Strong, vigorous roots are the secret to beating nematode problems. Your site preparation has reduced the population, and the new grass can get off to a good start. Encourage root growth by keeping the soil extra moist during the first few weeks of establishment; then water as needed.

Once established, water only when sections of the lawn start to show signs of stress by turning a gray-green color and curling the leaves. Then water the entire lawn as much as ¾-inch to rewet the soil profile, The stress exhibited by the wilting between waterings encourages additional root growth to help the grass resist nematodes.

Toughen up the lawn a bit more with feedings to encourage strong growth. Apply the first feeding three to four weeks after sodding. Use a 16-2-8, 15-0-15 or similar fertilizer to promote a pest resistant-lawn. Additional feedings typically are made in March, July and October.

Top

I recently moved to the Orlando area from Tulsa, Okla., and we prefer Bermuda grass to St Augustine, Bahia, or centipede types we see everywhere. we are building a home and would like to put down Bermuda grass. Is it not a good idea?

Bermuda offers several benefits, including drought tolerance, vigor and the thin-bladed look you and many residents would like in a turf. However, there are numerous problems that discourage its use as a home lawn. A few include the requirement of more feeding and a long list of pests that need to be controlled.

Bermuda grass lawns can be cut with a rotary mower, but many gardeners feel they look best cut with a reel mower. Keeping the manicured lawn also requires frequent mowing - often twice a week. Even though the turf survives drought, it turns brown without frequent waterings during the dry times. If you don't mind working regularly with your grass, you can have a good Bermuda lawn.

Top

A neighbor two homes away has a Bermuda grass-infested lawn. Should I be concerned the weedy grass will spread to my lawn?

Your lawn could become infested with Bermuda grass, but it probably won't be your neighbor's fault. Somehow the seeds spread from yard to yard even when everyone has the same grass. Maybe birds or other animals move the seeds or sprigs about. Burmuda grass may also enter your yard with sod or other plants. Your best defense is going to be cultivating a dense stand of the desired turf in your yard.

Make sure there are no openings for the Bermuda grass seeds to begin germination. A damaged area with missing turf is all it takes. Also infestations may come from flower or shrub beds where the weed seeds sprout and new growths creep out into the lawn. Keeping a normal healthy lawn and then being diligent about removing the weedy grass when first spotted is your best control.

Top

With all the rain we've had lately, I everyone in my subdivision has lots of mushrooms on their lawns. Should we pull them out or wait until they are mowed down?

As long as you and other family members and friends are not taste-testing these chlorophyll-free plants they are causing little harm to your turf. The fruiting tops of the mushroom last only a few days before turning brown and then shriveling. They do produce spores that could lead to other mushrooms, but there are probably plenty of new starts already in your yard.

Many mushrooms are poisonous and it's probably best to remove this temptation from the yard if there are animals or young children who could possibly eat the above-ground portions. Otherwise, most gardeners just enjoy this bit of nature and mow the mushrooms at the next cutting.

Top

I have a St. Augustine lawn that has grown progressively thicker. It's now difficult to push the mower through the grass. I heard dethatching or adding sand can help. What should I do?

Gardeners with that sinking feeling when they walk across their turf have an exceedingly lush-growing lawn often caused by overwatering and overfeeding. First check your care program and put the lawn on a lean diet.

Next comes the hard work. Dethatching can thin out the turf and get it to lie down closer to the soil, but it's often devastating to the grass. Often you end up installing a new lawn.

What seems to work best for many with this problem is sanding the lawn to fill in the voids. This gives the turf a new firm surface for growth. Up to an inch of sand or weed-free topsoil is often applied over the turf and watered in to form a new soil layer. With extras-spongy lawns, more sand may be needed, but give the grass time to become re-established between applications. Adding too much sand or topsoil at one time can cause rot problems and a decline of the lawn.

Top

I was told to apply a preemergence herbicide before laying new sod. Some of the grass is declining, and weeds are now growing in the area. I have noticed the sod did not root down. What should I do to grow grass in this area?

Adding the pre-emergence herbicide before sodding was bad advice. These products prevent seed germination but usually also stop roots of the new grass from penetrating the soil. The products can be active for up to 90 days. Also they do not control established grass and weeds. New shoots may emerge from stems of unwanted plants rooted in the area that was sodded.

Perhaps the best way to renew the green is to remove the declining turf and till the soil deeply to try and disperse any remaining herbicide. Then you can again add new sod. You may want to try just a piece or two at first to see if rooting is going to be inhibited. If the herbicide is still active, wait another month or two and try again.

Top

I have installed a new lawn and am concerned about the "bad bugs" and unwanted weeds that were left from the old yard. When can I treat the new lawn for these pests?

Adding a lawn normally disrupts the pests to the point where they are below damaging levels and the beneficial insects can maintain control. Hopefully, you controlled the problem weeds before the area was prepared for sodding. Normally, pests and weeds won't be a problem for at least several months, if at all this year.

Stay alert for declining areas in the lawn and treat when insects or diseases are diagnosed. These problems can be treated as needed as soon as the sod has been installed. Selective weed control products including seed germination inhibitors, knowri as pre-emergence herbicides, should not be applied until the new grass has become rooted into the ground.

Top

We had a nice St. Augustine lawn, but this year the weeds have taken over. Our pest-control company said the turf has been cut too low. What do you think happened?

Mowing the grass too close stresses the turf and makes it more susceptible to weeds. St. Augustine lawns of Bitterblue, Floratam, Palmetto and similar traditional types are maintained at the 3 to 4-inch height. The semi-dwarfs of Delmar and Seville are cut at about 2½ inches in height. But even with good mowing practices, weeds can sneak in.

After a hot, rainy summer with many prevalent pests, weeds are common. One control is to dig out or spot-kill the weeds as needed. Another is to apply a selective weed control product made for use in St. Augustine for the weeds listed on the label. Not all weeds are controlled by these products, so expect to continue pulling weeds by hand and maybe adding a few plugs or sod.

Top

I have an area of carpet grass and dollar weed. I plan to dig it out and then spray the area with Roundup. How long should I wait to resod the area?

Let's start by reversing the sequence of events. Apply the Roundup, Finale or similar weed-control product first. Then wait until the weeds begin to decline before you till the site and remove the debris. Rake the ground smooth, wet the soil and install the sod without further treatment.

Top

Our lawn was affected by a frost that turned portions tan. What should we do to encourage growth?

Allow the lawn to recover with normal care. Trying to regreen the turf quickly could lead to more damage during colder weather ahead. Water if the soil is dry. When the turf begins to grow during warmer winter weather, you can apply lawn fertilizer sparingly.

Don't be concerned about the affected leaf blades. They normally shrivel and are hidden by the new growth. If you find the brown too unsightly, the dead grass blades can be raked from the lawn as the growth begins.

Top

I have a St. Augustine lawn that occasionally develops small sections that turn a lime-green color. It seems to disappear after awhile. What could be the problem?

Most likely there has been some root damage to the turf that prevents it from taking up the needed nutrients.

The cause may be as simple as too much water during the summer months or as severe as rot and nematode damage.

Because the problem seems to cure itself, don't worry too much. Usually the nutrient that's lacking is iron, and it can be replaced quickly with an application of one of the iron-containing products found at your local garden center.

Top

I am planning to dethatch my St. Augustine lawn and aerate the ground. Which should I do first?

Most lawns don't need thatch removal; a good raking will do. Thatch accumulates below the runners or rhizomes of the grass and has a peatlike consistency. Seldom does it accumulate a layer thick enough to warrant removal in St. Augustine or Bahia lawns. If you have lots of brown grass blades after the winter weather, hand raking or mechanical raking should be all that is needed to renew the green lawn look.

Aeration can be of benefit if the soil is compacted or repels water. Hand and powered aerators punch holes in the ground and often remove a plug of soil to let air and water into the ground. Spring is a good time to aerate, just as growth begins. Follow the aeration with a spring feeding and watering.

Top

I have a number of weeds in my bahia lawn. Is it safe to use atrazine on this grass?

Nowhere on the atrazine label does it mention bahia grass. Use of this herbicide would at best turn the grass yellow and likely cause it to decline. Find another product that contains 2, 4-D, dicamba and related herbicides to use with bahia. There are numerous products on the market. Just make sure you follow the bahia instructions.

Top

I have a struggling St. Augustine lawn under several large oak trees. Should I allow the oak leaves to remain on the lawn and chop them up with the mower or remove them to make compost?

Oak leaves make a great mulch but not for the lawn. Ground up leaves even as small particles can contribute to the organic layer near the soil surface often referred to as thatch. The organic layer can impede water movement into the soil, bind up fertilizer nutrients and harbor lawn pests. It's best to rake the leaves, and add them to the compost pile.

Top

I recently bought a house with a lawn that had been neglected and contained several bare spots to which plugs had been added. What can I do to encourage the best growth from these sprigs of St. Augustine?

Water and fertilizer are the secrets to helping a lawn fill in with growth. Keep the soil moist by watering on your assigned days when the surface inch of ground begins to dry or the grass starts to wilt. Then feed lightly but frequently with a lawn fertilizer. An application once a month at half the recommended rate could be applied until the runners knit together.

Top

I have several low spots in my St. Augustine lawn. Can I fill them in or do I have to remove the grass? Also, what type of fill should I use?

Slight depressions in the lawn an inch or two deep can be brought up to the normal turf level with commonly used soils or similar substitutes. The grass that is in the lawn usually re-establishes itself in the new soil. Gardeners can select from clean topsoil, compost, builder's sand or the new lawn soils now appearing at garden centers. The use of topsoil is often the most risky as it may contain weed seeds net found in your landscape that are ready to germinate.

If the depressions are deep, you could still add the soil, but the turf likely would be lost. Many gardeners like to save the old turf by cutting out sections with a shovel or sod cutter and then adding the fill. After the fill has been brought up to the desired level and raked smooth, the saved grass can be installed. Provide normal care given newly sodded lawns until the grass is re-established.

Top

Our St. Augustine lawn is growing in a sandy soil that is hard to wet. I have tried a surfactant, but the water penetrates only about a half-inch into the ground. What else should I try?

Punching holes in the ground, commonly called aeration, can help the water penetrate deeper. A small hand-held aerator, available from garden centers, or even a pitchfork could be used to make holes a few inches apart throughout the problem area. Mechanical aerators available for rent make similar holes and are best used on large lawns.

The secret to success is watering immediately after aeration to help move moisture deeper into the ground. Thereafter, keep the soil moist by watering as permitted and re-establish the St. Augustine in the problem area.

Top

Our lawn has brown spots in several different places even though we water each section 10 minutes every other day. Is this sufficient, or should we water more often?

You are watering too little too often. First, under water management restrictions, watering is allowed only twice a week in most areas of Central Florida. Second; 10 minutes may not be long enough to wet the soil effectively.

Dig within the brown areas, and you are likely to find dry soil. These may be the harder-to-wet sections of the lawn, or sprinklers may not be hitting these areas. Also, ½ to ¾-inch of water is needed at each application to rewet the soil. It's doubtful 10 minutes of watering can provide this amount.

Readjust your watering schedule to comply with the local restrictions. Then set out cans or rain gauges to catch the water when you run the sprinklers. Set the system to run long enough to apply the proper amount of water as measured in the containers or rain gauges. You may have to readjust or add to the sprinkler system to water the brown areas properly.

Top

We have resodded our lawn. Do we need to treat the turf with a pre-emergence crab grass control?

Crab grass stops growing and germinating during the cooler fall and winter. Also, using a pre-emergence control product with new turf can inhibit the rooting. It's best to delay the crab-grass control until mid-February when the weather is warm enough again for the seeds to begin growth. If green crab grass is noted in the new lawn, it's best to hand-dig or spot-kill the weed and add sod.

Top

A sod company installed St. Augustine grass in our yard and in many areas left 2 to 3-inch gaps between the pieces. The workers filled in some of the gaps with soil, but I am concerned the remaining gaps will leave the yard lumpy and uneven. Do you have any suggestions?

Keeping the lumps out of the lawn could be as simple as adding a little more soil until the pieces of sod are even with each other. Use either lawn soil, potting soil, sand or the most weed-free topsoil you can find. The St. Augustine should start to fill in the voids during the fall and winter months to form a uniform and wellknit lawn.

Top

I have sandburs in my St. Augustine lawn. I was told the seeds are moved around by the person who mows. How can I control this weed?

If you are used to going barefoot, better keep your shoes on to avoid the sandbur's prickles. Eliminating this pest can take up to two years.

During the summer months, the only quick controls are to dig out sandburs or spot-kill them with Roundup or Finale. These products kill everything, so only treat what you plan to kill. A selective control of Image is also available at garden centers, but repeat treatments may be needed following label instructions.

Your best control begins in mid-February With a pre-emergence herbicide application. These products are the same ones sold forpreventing crab grass. Follow the label, and treat again as needed. And yes, the person doing your mowing could move the sandburs, also called sandspurs, from one yard to another, but usualy only during the fall when the seed heads form.

Top

I have a nice St. Augustine lawn, but within the past few weeks, a section of it has turned yellow. This section receives lots of sun and is susceptible to drying. What should I do?

As a professor of mine once said, water is deficient - but you knew that. Certainly this area is in need of water, and it could be as simple as a sprinkler not hitting the area or running long enough to wet the ground.

Try the water efficiency test of putting out several rain gauges or straight-sided containers in the area and turn on the sprinkler for 15 minutes. Then determine how much water was provided. Calculate the amount of time the sprinkler must run to provide up to three-quarters of an inch of water. Adjusting the sprinkler or watering schedule may solve your problem.

If you think the spot receives adequate moisture, maybe the water is not penetrating into the ground. Aeration can help open up the soil and let the water move into the root zone. If needed, use a pitchfork or manual aerator in small areas. For larger lawns, use the powered aerators available from rental centers. Immediately after aerating, water the lawn to wet the soil better.

Top

We sodded our lawn in November, and it looks great right now. What should we use to prevent insects like chinch bugs from causing the lawn to decline again?

Earth-friendly approaches to insect control are gaining in popularity. Out are the traditional spray programs to prevent insect attack, and in are monitoring techniques to control lawn pests as noted.

Possibly the best prevention technique is to walk through the landscape to detect symptoms of turf decline. Now that you know what a good lawn looks like, stay alert to yellow spots that begin to turn brown. This is the first symptom of chinch bugs. Then look for the pinhead-sized critters.

Gardeners are just beginning to realize there are many good bugs in the lawn. Many lawns will not need a spray this season, so why make costly, earth-damaging and unnecessary treatments?

Top

I have heard a 4-inch cutting height is best for St. Augustine grass, but my mower cuts only 3 inches high. The lawn gets thin in places. Is the 3-inch cutting height responsible?

Many mowers have restricted cutting neights for safety reasons. The 3-inch cutting height should be fine and isn't responsible for the thinning turf. Usually the sparse spots in lawns are because of shade or plant-root competition. Grass thins under these conditions and might never grow a thick lawn.

Top

I have a neglected spot in my yard that has filled in with a coarse, 3 to 4-foot high grass. If I cut it and treat what's left with Roundup, can I seed the area with bahiagrass or plant Asiatic jasmine?

Start with Roundup, Finale or a similar herbicide treatment that permits planting after the unwanted weeds decline. This allows the entire grassy weed to absorb the herbicide and move it down into the roots for total control. When the grass declines, you then have to decide what to plant.

If you are adding bahiagrass, cut the brown stalks to the ground and remove the debris. Then till the soil 4 to 6 inches deep. You can use the cooler months to prepare the soil, but wait until March to sow the seeds.

If you decide to add the Asiatic jasmine again, cut the brown grass stalks as close to the soil as ppssible. Leave the ground-up stalks on the surface as a mulch, and plant the ground cover through the residue. Complete planting by adding a more substantial 2 to 3-inch layer of mulch.

Top

My yard man tells me he cannot apply weed-and-feed on my lawn because he would be breaking the law. Is there a law that says we can't use these products on the lawn?

Your yard man might not be able to apply the product, but you can. Because weed-and-feed products contain herbicides, the applicator has to be a licensed professional or work for a company that employs a licensed applicator to supervise the work.

Your yard man can apply products that contain only the fertilizer. You have to leave the pesticide treatments to a trained and tested professional, or you can do the work yourself using combination products available at your garden center.

Top

Our St. Augustine lawn has lots of clover among the good grass. How can we get rid of the weeds?

Most clover-looking weeds in local lawns are oxalis, also known as wood sorrel, with a three-parted leaf and a yellow flower. This is a perennial plant that creeps across the lawn and would be rather attractive if it weren't growing among the grass.

Good control can be obtained with sprays of atrazine available from garden centers. Mix the herbicide with water, and then mist it across the surface of the weeds as instructed on the label. Allow the atrazine solution to dry on the leaves, and your oxalis should start to shrivel within days.

Top

My lawn has sections that have declined. Can I sod these problem spots and leave the good areas alone?

Having to reinstall an entire lawn is rare. Normally, just the weedy or pest-plagued areas can be removed and new sod installed. Try to determine the cause for decline and then make corrections as needed.

Good site preparation is always best even when repairing an older lawn. Control the problem weeds with Roundup, Finale or a similar herbicide. As they begin to decline, remove them and any remaining damaged turl. Usually the problem areas can be shaped into squares or rectangles that are easier to sod. Complete the preparations for sodding by tilling the ground a few inches deep and adjusting the soil pH if needed.

Top

I have a lawn area that has been damaged by a weed-and-feed-type product. A neighbor told me to seed the areas with ryegrass until the old lawn begins growing again. Will this work?

More than likely you are in for another failure. The weed-control herbicides in weed-and-feed products are normally good at preventing seed germination. Most are effective for 45 to 90 days. Overseeding with ryegrass is probably not an option this winter.

It's also more important to allow the damaged grass a competition-free time to recover from the herbicide injuries. Florida lawns can grow during the winter months, which should help with the recovery. Your job for the winter is to keep the soil moist and add sod to areas that have been severely damaged.

Top

I lost a small area of my lawn because of grubs. When is the best time to treat these insects, and what should I apply?

White grubs, the larval stage of certain beetles, are becoming a prevalent pest of local lawns. Turf decline because of their root feeding often resembles damage caused by chinch bugs, nematodes and some diseases. Gardeners have to look below the grass among the roots and in the soil to check for the insects. Remove at least a square foot of turf a few inches thick within the problem areas. Examine the root zones, searching for the plump white insects with three pairs of brown legs. If two or more grubs are counted in each square-foot sample, a treatment should be applied to the infested areas.

Winter is not the best treatment time because the grubs go deep in the ground. If you know grubs are the problem, consider delaying the treatment until warmer weather and use a lawn insecticide containing Dylox as instructed on the label.

If grubs are a continual problem, preventive treatments using the insecticides Merit or Mach 2 can be applied during May, June or July; follow label instructions.

Top

An area of our lawn had chinch bugs, but some good grass remains. Will the affected area come back on its own, or should we replace the turf?

You could wait and see what grows back, but realistically, the weeds normally win in the end. Save yourself a lot of grief and resod this area as spring growth begins.

To make sure chinch bugs don't creep in from the edges, apply a lawn insecticide around late March to ensure that these pests are under control.

Top

We noticed the chinch bugs rapidly ate the St. Augustine grass but stayed away from the bahia, What are the pros and cons of having a bahia lawn?

Bahia is getting a lot of attention lately because of its drought tolerance and chinch-bug resistance. It's a reliable grass, but many do not like its open habit of growth and coarse tex:ure. Also, seed heads that are a foot or higher pop up daily during the summer. Most bahia grass used for lawns comes from former pastures that are fed, manicured and then harvested to produce sod. With just a little care, it niraculously grows a good lawn. Bahia also can be established from seed.

Good-looking bahia lawns take several feedings a year and enough water to produce green growth. If you depend solely on rains for moisture, the grass goes dormant until the next storms. The grass has few pests and may see renewed use as residents deal with declining water resources.

Top

Our lawn is full of little, round, sticky things growing on short stalks. I've been told these are burs. I tried to eliminate them with a weed and feed, but it didn't work. What can I do?

Sticky things are no fun, especially if you like to go barefooted in the lawn. Most likely, your prickly weeds are sandburs, also called sandspurs. The good news is they can be controlled, but it's going to take about two years.

Work hard now: to stop the fall seeding. Where possible; dig out the growing plants or spot-kill them with Roundup, Finale or Nature's Avenger. You also can apply the selective herbicide Image sedge control, which affects the sandburs even though these weeds are a type of grass. Follow the label carefully.

All those little sticky portions contain seeds that are the start of the next sandburweeds. Most should not sprout until spring and can be controlled with a pre-emergence herbicide.

Choose one of the products labeled to prevent crab grass and apply it during February or March. Check the label and repeat the application as instructed to control sandburs that continue to germinate throughout the warmer months.

Top

My St. Augustine yard has become infested with creeping wood sorrel that looks like clover but has yellow blooms. What can I do to remove the weeds but not injure the grass?

Wood sorrel should start to disappear in about five days after an application of the herbicide atrazine available for use with St. Augustine lawns. Obtain the liquid product and apply it as instructed on the label, misting it across the top of the wood sorrel foliage. Avoid watering the lawn for a day or two, and your weedy turf should be pure grass again.

Top