Troops, let's talk about watering your turfgrass. As in mowing, I said, "High and slow." With watering, it is "Deeply and infrequently." Water composes from 75 percent to 85 percent of the weight of a healthy grass plant. It is essential for seed germination, tissue formation, plant cooling, food manufacture, and nutrient absorption and nutrient transport. A grass plant loses the most water under conditions of high light intensity, high temperature, low relative humidity, and windy conditions. Without adequate water, the grass plant can’t cool itself and becomes susceptible to wilting, desiccation, and death.
Are some grasses more drought tolerant?
Yes; grasses differ in both their need for water and their drought tolerance. Also, seedling or recently established lawns (less than 12 months old) have little drought tolerance. You must consider the proper planting time for the various grasses in order to successfully establish a lawn. Some mature grasses develop deep roots and require less water. However, the most drought-tolerant grasses may not be suitable for all regions of CONUS. Consult ME or your local agriculture extension agent for specific information for your area. Tall fescue, when properly managed, develops a deep root system and can be very drought tolerant. However, this advantage is lost if grown on shallow or extremely compacted soils. Kentucky bluegrass can survive extended drought periods by gradually slowing growth, turning straw colored and entering summer dormancy. Once water becomes available again, it can initiate new growth from the crown of each plant. Perennial ryegrasses have little tolerance to dry conditions and usually do not persist well in non-irrigated areas. Fine fescues such as creeping red, chewings fescue, and hard fescue tolerate dry periods quite well due to their low water requirements. Warm-season grasses such as bermudagrass, zoysiagrass, St. Augustine grass, and centipedegrass actually prefer warm conditions and can tolerate most drought conditions due to their deep and extensive root systems.
How much water does my lawn need?
This varies somewhat depending on grass type. In general, applying one inch of water per week is the recommendation when there is insufficient rainfall during summer drought. An inch of water can be measured by marking the side of a tuna or pet food can placed in the lawn. Remember, if nature provides water by rainfall, irrigation may not be needed. Nothing is more wasteful (and sure to attract attention for all the wrong reasons) than seeing irrigation running in the rain! Pay attention to current weather conditions and forecasts in order to use water more responsibly.
What about too much or too little water?
Over-watered lawns frequently lead to excess blade growth, summer fungal diseases, and more frequent mowing. Excessive watering also wastes water and increases the risk of fertilizer and pesticide runoff from the lawn to paved surfaces. This could negatively impact local water quality. Lawns that receive little to no water from irrigation or rainfall during summer months will go dormant. Grass blade coloring will lighten. Most lawns will recover when water returns. During a severe drought, cool season grasses (ryegrasses, fescues, or bluegrasses) may die and require reseeding in the fall. This may be acceptable to those looking to conserve water during summer months, or may be necessary because of water-use restrictions during a drought. Again, where warm-season grasses are adapted within the region, consider using them because they can better withstand most drought conditions.
How can I tell if my lawn needs water?
A “thirsty” lawn turns from the normal green color to a purple-bluish color. In these areas, the grass blades will not spring back if you walk across the lawn and your footprints are visible. “Foot Printing” is the first sign of “wilt” and indicates a need for water.
Tips for better watering
Deep and infrequent watering maintains a healthy root system and reduces weed infestation (as opposed shallow roots and germination of weed seeds). Applying one inch of water is often difficult to achieve in a single watering given the slow infiltration rate on most soils in the mid-Atlantic region. Therefore, smaller amounts of water applied every three to four days may be required to allow water to enter the soil without causing runoff. Water is best applied early in the day (0500 hours to 1000 hours) when evaporation loss is lowest. Afternoon watering is authorized but wind may affect uniformity. Night watering minimizes evaporation, but may increase fungal diseases. Consider that numerous automatic sprinklers all running during periods of high household use (like early in the morning) may place extreme demands on a community's water system. Water the lawn, not driveways, sidewalks, or roads, by adjusting sprinkler heads. Mow your grass at the right height during the summer (HIGH!). Longer grass blades increase the depth of the root system, shade the soil, and help drought tolerance.
So, troops, make it happen. Watering for 30 minutes each day at noon is not the solution. Water deeply, real deep, to the maximum root depth. Water the daylights out of your lawn (if you can afford it). Then wait for signs of drought stress. Then water it again at that time. Frequent, light waterings is a no go at this station.
Let me say a few more things about mowing....first....Cutting Height
How high should you cut your grass? Well, five factors determine the best cutting height:
Species
Use of the Area
Environmental Conditions
Turf Health
Mower Type
Turfgrass species is the main factor. The location of the crown for each species is different. Some species have elevated crowns so they would suffer from thinning and loss of vigor if the cutting height is too low. Unless you are preparing for a golf tournament in your yard, you should cut at the upper limit for the species you have. If you have a great deal of shade, cut it high to maximize photosynthesis. Temperature is also a consideration. When it gets hot; raise the height. Also, cut it high if the turf is recovering from some sort of stress or damage.
Scalping is the excessive removal of green shoots during mowing, causing a stubbly, brown appearance. When a lawn is scalped, root and shoot growth stop immediately.
Mowing Frequency
Mowing frequency should be determined by growth rate. And growth rate depends on environmental conditions, species and management principles. Under high growth periods, you may have to cut the grass more than once a week. Increased nitrogen fertilization and irrigation will stimulate growth.
A widely accepted rule of thumb is the “one third; two thirds” rule. Simply stated, remove no more than one third of the leaf tissue at any one mowing. Mowing too frequently is also a hazard. Mowing too frequently makes turf susceptible to disease because of repeated wounding of the leaf tips, which may allow fungi and other pathogens to enter the plant.
Turfgrass tends to grow or lean in the direction of mowing. Mowing in the same direction each time may allow a buildup of clippings in rows which can result in excessive thatch accumulation. Alternate your direction of mowing.
Mowing Equipment
Mowers basically have two cutting types: scissoring or impact. Reel mowers are scissor type mowers. They consist of 5 to 11 blades attached to a cylinder called a reel. They push the grass leaves against a cutting bar called a bed knife. Reel mowers are used in high quality turf areas like golf courses. They cut real close and make a beautiful stand. But they are expensive, hard to find and your ground must be perfectly level and smooth. There are some small "push" powered reel mowers. I recommend those mowers a lot for Warriors who have real small lawns, like around a townhouse, or for Warriors on the overweight program.
An impact mower is what most of us are familiar with – a rotary mower. It cuts the leaves with blades that rotate horizontally at high speeds. The mower cuts the grass by the sheer speed of the blade.
With either type of mower, having sharp blades is the culminating point in this battle. Sharpen your blades each year before mowing season. Dull blades can reduce the quality and heath of the turf drastically. Now, sharpening blades may throw them out of balance. If you or Bubba at the local hardware store do not know how to properly sharpen blades, and balance them, don't do it. I just buy new blades and recycle the old ones.
Do not mow when the grass is wet. That tends to rip, shred or pull the grass.
Returning grass clippings to the ground is a touchy subject. Too little has no effect. Too much can create thatch and can eventually choke out a lawn – by not allowing air, water and other nutrients into the soil. Decomposition of some clippings provides nutrients. But, too little doesn’t do anything and too much can be a bad thing.
Always cut at the highest BLADE SPEED possible. The mower should move slowly. Let the blades do the work.
HIGH AND SLOW - that's what I always say.
Mandatory Annual Safety Briefing
Each year more than 110,000 great Americans are injured using lawn mowers. Here's what the Army Corps of Engineers has to say about mower safety:
Lawn Mower Injuries:
§The power lawn mower is one of the most dangerous tools around the home.
§The U.S. Consumer Product Safety Commission reports that each year lawn mowers injure over 110,000 people seriously enough to require treatment in hospital emergency rooms.
§More than 9,000 of the people hurt were younger than 18 years. Older children and adolescents were most often hurt while cutting lawns as chores or as a way to earn money.
§Injuries include deep cuts, loss of fingers and toes, broken and dislocated bones,burns, and eye and other injuries. Both users of mowers and those who are nearby can be hurt.
Four types of power lawn mower accidents cause the majority of injuries:
§Contact with rotating blade.
§Propelled objects. Rocks, glass and wire are hurled at initial speeds above 170 miles per hour. Objects may be thrown 50 feet or more.
§Overturning. Thi soccurs primarily when riding mowers are used on steep slopes or embankments. Victims may be pinned under the mower or come into contact with the blade.
§Riding mowers running over the victim. Accidents occur if the operator fails to look when backing a riding mower, children playing are seriously injured, or an operator pulls a power mower backward over his or her foot.
Other Hazards:
§The muffler and cylinder head heat up during operation, and remain hot for sometime after the engine has been turned off and can cause burns.
§Most mowers are powered by gasoline-driven combustion engines. Gasoline is a very explosive and flammable material that should be treated with respect. Gasoline is flammable because it vaporizes with air to form a mixture that ignites easily. Vaporization can occur in temperatures as low as zero degrees.
Follow these guidelines:
§Read the operator’s manual. The manual explains safe procedures that should be followed
§Check guards and shields. Be sure all protective devices are in place before starting the mower. Shields and guards are for your protection and will prevent injuries if used.
§Don' tmow when other people are nearby.
§Wears trong shoes or boots, not flip-flops or sneakers.
§Pick up rocks, sticks, pine cones, and toys before mowing, even if you are using a mower that collects the clippings automatically.
§Wear goggles or safety glasses, and wear hearing protection. Once you get used to protecting your hearing, you'll be amazed at how annoyingly noisy a mower is when you aren't wearing protection.
§Fuel your edger and mower outside, and do it before you start, not during operation.
§If you are going to remove or replace the blade, disconnect the spark plug first.
§Turn off the mower and wait for the blade to stop spinning before you empty the grass catcher, unclog something from the blade or under the mower, or push the mower across rocks or gravel.
§Riding mowers aren't meant to carry passengers.
Caution…
§Make sure other people, especially children, are out of the area. Young children should be supervised while the yard is being mowed. The mower operator may no thear or see children approach.
§Never point the discharge chute at anyone. Never run the mower over gravel.
§Do not mow wet grass. Wet grass is slippery and the operator can lose footing, slip under the mower, or allow the mower to roll backwards. Wet grass also clogs the discharge chute and can cause the engine to falter. When this happens, always turn off the engine and wait a few seconds for the blades to stop rotating before correcting it.
§Use care on inclines. Some slopes are too steep to mow safely. Always push walk-behind mowers across slopes to avoid coming in contact with the mower (e.g., by sliding down the hill onto the mower, or allowing the mower to roll backwards on top of operator). Drive riding mowers up and down slopes.
§Never leave a running mower unattended.
Do your PMCS (Preventive Maintenance Checks and Services), wear the right gear and be aware of your surroundings. Hooah? ESSAYONS!
I want to expand this section on turfgrass insects. If you refer back to one of my earlier categories – “Lawns We Are Working On” – you will see where I answered Marc’s question about grubs (Wednesday, March 06, 2013, 6:15 PM). When you feel like it, please review that section. I won’t bore everyone with repeating that information on white grubs. Also, in response to that question, I started this section on turfgrass insects and I posted a drawing and a picture (above & below) of a lawn grub.
Now, I’ll provide some more information regarding turfgrass insects.
Insects are all around us. They are some of the most plentiful creatures on this planet. They are 70 to 80 percent of all known animals. There are over a million species of insects on earth and the US has about 100,000 different species. But, the good news is; less than 3 percent are a nuisance to plants or people. As I said in my post referenced above, less than 100 species attack turfgrass.
A true turfgrass warrior should have at least a basic understanding of insects and how they form, their life cycles and how they damage our turfgrass. What are they and where are they? If you can’t operate the internet, you wouldn’t be reading this. So, in this blog post, I can give you the basic information and then you can search from here.
Insects go through a progression of changes in their life cycles called metamorphosis. There are two categories of metamorphosis – simple and complex. When an insect develops from an egg into a larva, or a worm-like organism, that is a complex (or complete) metamorphosis. Like the larva of a butterfly is called a caterpillar. Larvae eat a lot. This is the stage when the insects that attack turfgrass cause the most damage. Then the larva goes through pupation to become an adult. Most turfgrass insects go through complete metamorphosis.
The insects that have simple metamorphosis do not have a larval stage. They hatch into nymphs which are merely smaller versions of the mature adult.
Insects have three main body parts: the head, the thorax and the abdomen. And, the insects that damage turfgrass have two different types of mouths – chewing and piercing-sucking. They either chew up pieces of the plant tissue or they suck the juices from the plant tissue with an extended, hollow, beak-like extension or siphon.
Here I will list the common species of grubs and where they are usually located.
Japanese Beetles: most common east of the Mississippi River but can be found throughout the US.
Green June Beetles: primarily found in the east from NY to FL, but can be found as far west as TX & OK.
European Chafer: mostly found in the northeast, with some in MI & OH.
Southern and Northern Masked Chafer: the Southern masked chafer is found east of the Rockies but most likely in KY, IN, IL, MO & TX. The Northern Masked Chafer can be found from CT west to OH & MO.
May or June Beetles: mostly found in eastern CONUS. Less likely to be found on the west coast or southwest.
Black Turfgrass Ataenius: found usually on golf courses or other intensely managed turf. Can be found in the north Atlantic coast and the Midwest.
Oriental Beetles: Found in NY, CT, MA, NJ, RI, PA, NC & HI.
Asiatic Garden Beetle: can be found in most northeastern states and along the Atlantic coast from MA to SC.
Here are some more “soil inhabiting” insects:
Billbugs
To the left is a picture of an adult Billbug. These insects have bills or snouts. These can be found throughout the US. There are basically three species: the Hunting Billbug, the Phoenix Billbug and the Bluegrass Billbug. The larvae have no legs. Unlike turf damaged by grubs, billbug damaged turf cannot be rolled back like a carpet. Turf damaged by Billbugs will pull away easily because the chewed stems break away from the crown. If you have Billbugs, you will most likely see some fine, tan sawdust-like excrement that accumulates in the feeding area. Turf damaged by Billbugs will have firm soil whereas turf damaged by grubs will have loose soil. Below is what Billbug damage looks like.
Mole Crickets
These can be found in the southeast US, especially in FL, and along the south Atlantic and Gulf Coasts. There are two main species: the Southern Mole Cricket and the Tawny Mole Cricket. Mole Crickets have shovel-like front legs which actually cut the turfgrass roots.
They also feed on the roots. They go through simple metamorphosis, so the nymph looks like the adult. Usually a soap solution is applied to see if Mole Crickets emerge. Insecticides can handle the Mole Cricket. To the right is a drawing of a Mole Cricket.
Ground Pearls
These can be found in the southern and southwestern states. They look like miniature pearls. They are actually a type of insect called: Scale. They have piercing-sucking mouth parts. Not much is known about their life cycle. They attack Bermudagrass, Zoysiagrass, Centipedegrass and St. Augustinegrass. They can go as deep as 10 inches so fighting them can be tough.
European Crane Fly
Most likely found in the Pacific Northwest. They are tough; that’s why they are called “leather jackets”. The adult looks like a large mosquito. They do not harm people or property. They feed on turf roots and crowns. There are some preventative insecticides out there.
Below Are Thatch Inhabiting Insects:
Sod Webworms
These are the larvae of “lawn moths”, sometimes called “millers”. They can be found in most regions of the US and they like to feed on Kentucky Bluegrass, Perrenial Ryegrass, Fine Fescue, Bentgrass, Bermudagrass and Zoysiagrass. They differ from other moths because they fold their wings around their body, making them look real thin. That also makes them hard to see. They also have a snout-like projection from the head. They hide during the day. But, if disturbed, they will fly a few feet. They feed on the leaves just above the crown. The first sign of damage is yellow patches of turf. Large numbers of these moths flying just above your turf in the early evening is a bad sign. But, they can be easily controlled.
Cutworms
Cutworms are larvae of night flying moths too, but they are easily 2 to 3 times larger than the Sod Webworm. They feed on the turf at night and lay curled up in the turf during the day. They cut the turf and pull it into a burrow in the soil before eating it. You can detect them by seeing turf leaves that are unevenly chewed or severed. You may even spot their green excrement pellets. These can be easily controlled as well.
Armyworm
Armyworms are like caterpillars that attack turfgrass. They are found throughout the US – east of the Rockies. There are two species: The Armyworm and the Fall Armyworm. The larvae feed at night. They feed on the lower surfaces of the leaves. They can be very damaging. A horde of Armyworms can devour all the grass in an area and move on quickly. But, they can be controlled.
Chinchbugs
There are the Hairy Chinchbug and the Southern Chinchbug in the US. The hairy species is in the northern states and the southern one likes warm season turfs, especially St. Augustinegrass. They have piercing-sucking mouth parts. They suck out the juices and, in doing so; inject a toxic fluid into the plant tissue. Detection and control are fairly easy for Chinchbugs.
Leaf & Stem Inhabiting Insects
Mites
Mites are arachnids, not really insects. They have eight legs and two body parts. There are: The Bermudagrass Mite, Winter Grain Mite and Clover Mite. Bermudagrass Mites are very tiny and only feed on bermudagrass. Winter Grain Mites are only active in the winter. Clover Mites are so small they look like little, reddish specks and will leave a reddish stain when crushed.
Frit Flies
The larvae of these flies (aka maggots) feed on most cool season grasses. Their tunneling also destroys stem tissue. You can detect them because they are attracted to white. Throw down a plain white piece of paper and they’ll hop right on it.
Greenbugs
These are aphids. They attack about 60 species of turfgrass. They have piercing-sucking mouth parts. Like Chinchbugs, they suck out fluids and inject a toxin. The damage usually begins with turf in the shade. There can be as many as 4,000 in a square foot.
Leafhoppers
Both the adults and nymphs pierce and suck the leaves and stems. They can be detected as you walk through the lawn. They will “hop” or jump as you disturb them. Control is difficult because they can infest, cause damage and move away from the area so quickly.
Other Pests
These other pests may not feed on or damage turfgrass. But, they may build mounds or make holes. Or, they may be a nuisance to people or pets. These are:
Red Imported Fire Ant – Can make very large mounds and sting people.
Cicadas – They can be loud and there can be lots of them. Good thing they only come around every 13 or 17 years.
Sowbugs & Pillbugs – These sometimes feed on turfgrass or other succulent plants.
Millipedes & Centipedes – Centipedes in the south can sting you.
Slugs and Snails – These are mollusks. They may feed on other flowers and shrubs.
Fleas – These can get on your pets and then on you. There are insecticides to treat your yard if this becomes a problem.
Ticks – May cause anemia and transmit disease (like Lyme Disease). A female tick can lay as many as 6,000 eggs.
Spittlebugs – These suck plant juices. They hide in a froth-like substance they create. They rarely cause damage.
Chiggers – Immature larvae of certain mites. Spray-on or lotion repellants usually work on Chiggers.
Earwigs – They feed on other plants but do not damage turf or bother people.
A few final words about insect control….
It is not economically feasible or practical to absolutely eliminate all your insects. It just can’t be done. The goal should be to contain the problem enough to where there is little or no damage to your turf and little or no nuisance to yourself when working in or enjoying your yard. There are so many factors affecting the insect population in your AO (Area of Operation); climate and predators are just a couple factors. It is hard to control all the variables.
I will discuss pesticides later in a separate post.
One thing is for sure. For many of these pests, you will not be able to make any sort of diagnosis from your deck or patio. You’ll have to get on your hands and knees, and maybe even have at least a 20 power lens to see what’s going on. Your neighbors may think you are a freak. But you will have a better lawn.
Dave,
Thanks for your request.
There’s not much to say about a RASTER. It is just part of, like the tail end of, a white grub or chafer/beetle larvae. These pests are a real problem in the northern Midwest. Now, that being said, the raster (or the “raster pattern”) is the most common way to identify which species of white grub a turfgrass troop may have in his or her AO. The shape of the anal slit can also be used in identification. Determining the correct species provides a better way to develop a management strategy. Ohio State and Michigan State University have great fact sheets for identifying grubs.
There are some methods to remove white grubs. I talked some about grub control before, but here are some other ideas:
1. Keep your lawn healthy. Do the management practices I’ve talked about throughout this blog.
2. Aerate. Grubs prefer compacted soil.
3. Keep a lookout. Turf will turn brown and wilt. The turf could be rolled back like a carpet or rug because the grubs sever the roots. Look for skunks or moles feeding on grubs.
4. Water deeply.
5. Think about using milky spore. (But that only works on Japanese beetle grubs; those are the most common though.)
6. Consider using parasitic nematodes. That’s a stretch though…
7. Use “the spikes of death” lawn aerator attachments to your shoes. They are terrible for aerating but you might get the picture.
8. Try a mixture of diatomaceous earth mixed with soap powder at a rate of 6 to 9 kg per 100 m2. Alternately, use a tablespoonful of pyrethrum dissolved in 4 L of water. Spread either one of these mixtures across the infected area of the lawn.
9. Use a fertilizer high in potassium in the fall.
10. Then, there’s always chemical control……
Spittlebugs are a different story. They are moth like black bugs with the orange stripes. They are much like aphids. For protection, spittlebug nymphs release a mass that looks like spittle, hence the bugs' name. It serves to protect the nymphs. The insects can do serious damage to grass, especially the centipede variety. They fly about while you are mowing or walking through the lawn.
Spittlebugs feed on plants by inserting needle like beaks into the stem and suck out juices. Unchecked, this can cause grass to become bleached or yellow, then eventually wither and die. The symptoms are similar to the damage caused by chinch bugs in St. Augustine, but spittlebug adults are much more mobile than chinch bugs, so the damage tends to be spread out, rather than concentrated.
Spittlebugs overwinter as eggs in plant stems, under leaf sheaths or in plant debris. Nymphs hatch in the spring and begin feeding. The nymphs feed for about a month before becoming adults. Adults live about three weeks and lay eggs the last two weeks. The eggs take about two weeks to hatch. Two generations hatch each year.
Adult spittlebugs are about a quarter-inch long and black to dark brown. They have two bright red or orange stripes across their wings. Nymphs resemble small wingless adults. They're white to yellow-orange with red eyes and a brown head.
Early on, a damaged lawn will have yellow spots of dead or dying grass. Spots might overlap to form large areas of dead turf in heavy infestations.
The nymphs are easily detected. Just look on the grass stems near the soil surface for the distinctive spittle masses. In severe infestations, you can actually hear a squishing sound as you walk across the grass.
Adult spittlebugs also can damage ornamental plants, particularly in late summer and fall, when populations are at their highest levels. The ornamental plants they prefer include hollies, asters and morning glory. If spittlebugs feed on woody plants, the new growth will be twisted and deformed and the leaves will have irregular brown blotches.
Infestations can be controlled with turf insecticides that contain pyrethroids, such as bifenthrin (Ortho Max Bug-G-Gon), cyfluthrin (Bayer Advanced Multi-Insect Killer), cyfluthrin+imidacloprid (Bayer Complete Insect Killer), or lamba-cyhalothrin (Spectracide Once and Done Insect Killer).
Use plenty of water to apply the insecticides since you need to move it through the thatch layer of the grass and into the soil. When using a liquid insecticide, you can achieve the best volume of water with a hose-end sprayer. Spittlebug infestations are worse in a rainy summer or if a lawn has been over-watered.
The nymphs need high humidity to survive. Turf with excessive thatch is much more likely to provide them the conditions they need. This occurs when centipede is mowed higher than it should be. Reducing the mowing height will cut down on the spittlebugs' numbers.
Hope this scratches your itch!
TW