Lawn Tips
How to Deal with Many Lawn Care Issues
Apple Scab
Apple scab is a common disease of apple and crabapple trees causing spots and lesions on the foliage and fruit, often resulting in early defoliation of the tree. The disease is more prevalent following wet spring weather. Some varieties of trees are naturally resistant to the disease while other varieties are extremely susceptible. Fungicide treatments applied to susceptible trees can greatly reduce infection.
Bagworms
Bagworms are commonly found on evergreen plants such as arborvitae, spruce and juniper, but will also attack many deciduous plants as well. The larvae construct the “bag” from silk and bits of plant material and will carry this bag with them as they feed. When disturbed, the larvae retreat inside the bag for protection. Hand picking or insecticide treatments during the summer feeding season will provide the best control.
Crabgrass
Crabgrass is a very invasive summer annual grassy weed that can only be controlled with a spring application of pre-emergence herbicide. A single mature crabgrass plant can produce up to 1,000 seeds annually that can lay dormant in the soil for up to 10 years. Emergent herbicides alone only reduce the potential for crabgrass and other annual grasses to germinate. A combination of herbicides, good cultural practices (mowing and watering) and over-seeding is required to thicken lawn and prevent weed seed germination. Crabgrass most often occurs around edges and thin areas for two reasons. The first is from the use of mechanical string trimmers which can destroy the herbicide barrier when improperly used. The second is from increased sunlight penetration which will more rapidly break down the barrier.
Chinchbugs
Hairy chinchbugs live in the turf thatch layer of your lawn and affect Kentucky bluegrass similarly to the way a mosquito affects a person except with more damage. The chichbug's bite the leaf tissue to suck out the juices and in the process inject a toxin which damages the turf's vascular system and may kill the turf. Chinchbugs are easily observed when active by looking at the border of the living and dead turf. Carefully part the turf, look down into the thatch and count to five. If they are active you will quickly see many tiny little black bugs with white crosses on their wings. Chinchbugs have two generations per year in southern Ohio - in late spring and early fall. One insecticide application in the spring should control both generations.
Dollar Spot
Dollar spot is a summertime disease that affects Kentucky bluegrass lawns, golf course turf and annual bluegrass. The affected areas show very distinct “Silver Dollar” size spots and the individual grass blades have tan stripes with copper colored bands above and below the straw-colored centers. When the damaged leaf blades collapse, the turf takes on the dollar spot appearance. If left untreated, these spots can grow together and spread damage throughout the lawn. Traditional fungicides are not used on residential lawns because of high costs. Corrective cultural practices are more effective than fungicides and resistant bluegrass blends are available for over-seeding Reducing irrigation will keep the leaves dry and reduce disease development.
Grubs
Grubs are the most well-known and easily identified turf insects. They are the larva stage of the Japanese and other adult beetles that feed on your landscape plants during the spring and summer. After feeding, the beetle lays its eggs in the warm, moist soil. After the eggs hatch, the grubs start feeding on all organic material in front of them. Turfgrass is easily killed by grubs because the roots are destroyed near the base of the plant. Grub damage is easily identified because patches of the turf will turn brown and can be easily lifted up like a rug. It generally takes 8 to 12 grubs per square foot to damage a lawn. At 4 to 6 grubs per square foot, the lawn will not be directly affected but can be damaged by skunks and other animals digging for them.
Japanese Beetles
Japanese beetles are the adult stage of the Japanese beetle grubs that feed on turf plants. Adult beetles are active from mid to late summer and will feed on over 200 varieties of plants. Insecticide treatments applied to susceptible plant material will reduce feeding damage. Beetle traps are not generally recommended as the traps tend to attract more beetle than they actually capture.
Leaf Spot
Leaf spot is a very common disease affecting bluegrass and most lawn turfgrasses. The pathogen causes yellow, brown and black lesions to appear on the diseased leaf tissue. Extended cool, overcast and wet periods in the spring may cause large areas of the turfgrass canopy to “melt out”. The leaf spotting or leaf blighting is less damaging to the plant than is the melting out (crown and root rot) phase of the disease. In the melting out phase, the crowns and roots are damaged, causing severe thinning of the turf. Good cultural practices will do more to correct the disease incidence than traditional fungicides. Manage your spring nitrogen applications, irrigate only for turf health and mow frequently to slow leaf spot damage.
Mower Stress
This photo indicates clear evidence of the damage that can be caused from improper mowing. Mowing height, mowing frequency and keeping the mower blades sharp are critical to the overall appearance of your lawn. Second to watering, it is the most important cultural practice. The recommended mowing height for bluegrass lawns in southern Ohio is 2 1/2 to 3 inches; 3 to3 1/2 inches for fescue lawns. Turf should be cut shorter in early spring and late fall to reduce disease incidence and promote shoot growth. Lawns that are mowed high (3 to 3 1/2 inches) conserve more moisture, shade the soil and develop deeper roots than lawns cut short. Mulching mowers return valuable nutrients and add organic material back to the soil. Contrary to popular belief, leaf clippings do not add to or accumulate in the thatch layer
Necrotic Ring Spot
Necrotic Ring Spot is a serious disease of high maintenance Kentucky bluegrass sodded lawns. Initial symptoms are patches 6 to 24 inches in diameter with mixture of normal, straw and red-colored blades around the outer portion of the ring resulting in a “frog eye” appearance. Thatch may decompose in the patch, giving a depressed appearance. Necrotic Ring Spot is a very difficult disease to control because it originates in the soil and therefore affects the crowns and roots of plant before damage appears on the leaves. Once Necrotic Ring Spot is established, it is difficult to control and damage may remain or reappear for 2 to 4 years. Control requires a combination of early detection, thatch control, relieving soil compaction, changing of watering practices, over-seeding with resistant varieties and possible use of fungicides. Perennial Ryegrass and Tall Fescue are resistant to Necrotic Ring Spot.
Nutsedge
Yellow nutsedge is a weed that closely resembles grass and is often mistaken for a wild grass. It appears in early summer and quickly takes on a pale green appearance. It is easily recognized because it grows faster than the surrounding turf. Closer inspection will show that unlike a grass blade which is flat, nutsedge has a triangular blade. Yellow nutsedge is most prevalent in lawns or sections of lawns that drain poorly or hold water and generally the wetter the spring, the more nutsedge you will see. Nutsedge can only be controlled with a post-emergent herbicide treatment. Please contact your route manager if you observe yellow nutsedge in your lawn.
Quackgrass
Quackgrass is a wild perennial grass that is undesirable in all turfgrass stands. Quackgrass is best identified by its clasping auricle (see photo). It is most noticeable in the spring when its color appears more blue than green and is faster growing than surrounding turf. As the spring progresses, quackgrass will become less noticeable. Quackgrass is most common in lawns that are near agricultural fields where the seeds can blow over and germinate in thin areas. Once established, quackgrass can spread quickly through the lawn by underground rhizomes. Selective chemical controls are limited. In most cases, the lawn or sections of the lawn will need to be renovated to remove quackgrass.
Red Thread
Red thread is a wet weather disease that is primarily a problem on perennial ryegrass and fine fescue but can occur on all cool season grasses. This disease is characterized by pinkish-red strands located at the tip of the grass blade. Effects of the disease are largely cosmetic and will create an undesirable appearance, but the crowns and roots are not affected. Red thread is usually not treated with traditional fungicides because of the cost and because most turf will recover on its own. Most diseases will require constant moisture to survive. If we can keep the leaves dry as much as possible, the disease incidence will decline. Supplemental nitrogen applications can be used as a solution but adding soluble nitrogen to some grass varieties may actually increase leaf spot and brown patch.
Root Girdling
Synthetic twine and burlap, wire baskets and natural root malformation can cause disruption in the sap flow of the tree. This problem often develops several years after a tree was planted and the trunk and roots have grown in diameter to a point where a constriction of the sap conducting vessels occurs, resulting in the decline of the plant.
Spider Mites
Spider mite injury is caused from the mite mouthparts damaging the plant cells in order to ingest the sap. Mite feeding can cause stippling patterns on the leaves, resulting in a gray or bronze appearance to the plant. Common insecticides are often ineffective in controlling mites and in some cases can increase the mite population. Special miticides and proper cultural practices are required to keep mites under control.
Tall Fescue
K-31 Fescue in its wild varieties is used as a ground cover along roadways and other municipal areas. When one or more clumps of K-31 variety finds its way into your bluegrass lawn, it can ruin your lawn's appearance. The wild varieties are coarse-bladed, pale in color and grow only in clumps. Tall fescue growing in a Kentucky bluegrass stand takes away from the overall appearance of the lawn. However improved or turf-type tall fescues in seed blends and mixes often make the best lawns. Over-seeding a bluegrass lawn with improved tall fescue will result in improved drought, insect and disease resistance. Selective chemical controls for tall fescue are limited. The clumps will need to be sprayed with a non-selective herbicide such as Roundup and then reseeded/sodded. In extreme cases, total renovation is required.