Lawn problems are difficult to diagnose, and the diagnosis process can be quite complex. Remember that most turfgrass problems are caused by improper management practices, not by insects or diseases. Before you begin the diagnostic process, take a look at how you manage your lawn. You may be able to solve your problem by simply changing your cultural practices.

While the best protection from lawn problems is preventative maintenance, even homeowners who are deeply dedicated to lawn care sometimes find themselves dealing with certain lawn ailments. Lawn diseases and problems are tricky to properly diagnose so it’s best not to try treating the disease or problem by yourself. When it comes to diagnosing and treating lawn problems, it is best to call a lawn care professional who can identify the problem and create the best treatment plan for your specific needs.

What Causes Lawn Problems?

Soil is the foundation of your lawn. All soil contains beneficial fungi critical to plants’ ability to thrive. Beneficial fungi help to break down organic matter and play a key role in helping plant roots absorb nutrients. The more beneficial fungi in your soil, the better chance your lawn has of warding off disease. In addition to beneficial fungi, soil contains microscopic bacteria, fungi, phytoplasmas and nematodes that can hinder the ability to maintain a healthy lawn. The majority of lawn diseases, however, are caused by pathogenic fungi. When it reaches high levels in soil, disease development will occur as soon as the environmental conditions favored by the fungi are present.

Regular and seasonal lawn maintenance is a necessity for all homeowners because it helps to equip your lawn to fight off disease. Lawns with inadequate nutrient levels are most at risk, so regularly checking your soil health and practicing both seasonal lawn care maintenance are crucial. There is an art to proper fertilization, watering and mowing, and these three factors can make or break your lawn.

Below is a list of common lawn problem causers. This list is not exclusive but should provide a start to your diagnosing needs.

Mowing Problems

Length of Cut
Mowing, although a common practice, is often very abusive and misunderstood. Most turf grasses should not be mowed shorter than 1.5-2 inches. Shorter grass reduces the surface area (the food producer) so that the plant may not have the ability to produce the food it needs. It will then draw more from the roots. Although sustainable for some time, eventually the practice will catch up for the plant. It will be especially noticeable in hot, dry weather.

Mowing frequency
Infrequent mowing (generally less than once a week), which has become fairly standard with new mower technology, cuts off too much of the blade at once. This can shock plants and trigger them to use root reserves rather than usual photosynthetic production. By standard rule no more than 1/3 of the blade should be removed at once. Also excessive clippings left on the grass can smother it which can harm the grass or even kill it. This also creates an incubator for fungal and diseases to develop.

Chemical Problems

Lack of Fertilizer Overlap
Although missing areas of lawn with fertilizer might not be considered actual damage it does result in a weird looking lawn. Fertilized areas will be dark green while the missed areas will be a pale green, or even yellow shade. Fertilizer doesn’t leach much so it is important to apply it evenly on the entire turf area.

Fertilizer Burn
Fertilizer can burn the lawn if applied excessively (much less common than believed). Chances of burn are increased if applied with the grass is wet and it isn’t watered soon after. (Some types of fertilizer require grass to be wet during application, so read the instructions first.) Nitrogen is the fertilizer element most likely to cause a burn. Most fertilizer burns occur in a small area where fertilizer is spilled or comes out the spreader in a pile.

Grass may become pale green or yellow, and plant growth may be stunted. Often this condition is due to lack of nitrogen. If a nitrogen fertilizer application does not correct this condition, it is very likely that the cause is iron deficiency. An application of iron sulfate or chelated iron on grass with iron deficiency should result in greener grass within a day of application.

Herbicide Injury
Even selective herbicides (2,4-D for example) or other dandelion/broad-leaf weed killers used to control specific weeds may hurt or kill grass if applied at rates exceeding recommendations. Don’t exceed the manufactures recommended rates and you might have to actually measure as most people get in trouble pouring from a bottle trying to guess how much 3 oz is. Chemicals sprayed off of the lawn can even leach into the lawn. This is common when the lawn is lower in elevation than the area sprayed. Rain or irrigation water could also cause these chemicals to move so be careful when spraying even away from the grass.

Over or under watering a lawn will have negative effects. This is a whole topic in and of itself and is discussed in more depth in a previous blog post. Not only will over watering hit your pocket book but it can also cause a surface crust to develop which will make watering harder and less efficient in the future. Over watering will cause root growth to stunt and encourage weed germination and disease development. Frequent shallow watering may keep upper soil layers constantly wet. This condition encourages shallow root growth and promotes weak turf which is susceptible to disease and insect attack as well as damage from traffic.

Confined Dry Spots
Dead or injured spots often develop in turf areas because of lack of water, even though surrounding turf shows no drought injury. (Lack of water doesn’t always mean it isn’t being watered or that the sprinklers aren’t working properly.) Buried debris such as concrete, rocks, bricks, or , construction debris, or gravel may result in a thin soil in the area. This soil layer has a low water-holding capacity and dries out very quickly and therefore needs water more frequently and will never develop deep roots. Thatch or clay soil could also cause problems with water absorption.

In hot weather heavy foot traffic on bluegrass or fine-leaved fescue turf usually indicates that the turf has reached its wilting point and must be watered to maintain green color. When watering, soak the soil deeply; then don’t water again until the turf shows signs of wilting.
A different type of foot printing may be observed in late winter or early spring. The turf may be injured if it is walked on when grass blades are frozen or frosted. Walking on these plants can rupture the cells causing plants to die.

Winterkill happens most frequently during late winter months. Damage occurs most on high, exposed areas which frequently have very low soil temperature and are subjected to strong, drying winds. In late winter the top inch or two of soil often thaws; air temperatures are favorable for grass growth, but roots imbedded in a still frozen ground are unable to take up enough water (if any) to satisfy the plant’s needs. The turf, therefore, dies from lack of moisture. This can occur on a smaller scale where grass doesn’t die, but when late spring or summer heat arrive the roots are so damaged and shallow that there is virtually no heat tolerance and the grass dies.

Soil Problems

Soil Compaction
Soils of poor physical condition or those subjected to play or heavy traffic (especially when wet) form an impervious surface layer which prevents water infiltration, nutrient penetration, and gaseous exchange between the soil and the atmosphere. Under these conditions turfgrasses may thin out and be replaced by weeds such as knotweed, which flourish on compacted soils. Aerators will remove soil plugs or cores, creating an artificial system of large pores which will permit moisture, nutrients, and air to enter the soil and help reduce the compacted condition.

Winter Scald
Damage from winter scald may occur where poor drainage permits pooled water to freeze. Heat from the sun shining through this layer of ice can initiate growth. As no gaseous exchange can occur through the ice, some turf may die. The only solution is to correct the drainage problem.

Summer Scald
Poorly drained areas subject to water pooling for short periods may be seriously damaged by scald. Summer thunderstorms may release large amounts of water in a short period; if the storm is followed by clearing and a hot sun, the sun’s action on the pooled water will produce anaerobic conditions which cause damage. As with winter scald, the only practical solution is to improve drainage.

Other Problems

Layers of partially decomposed leaves, stems, and roots at the soil surface will build up over a period of years. Thatch decreases turfgrass vigor by restricting the movement of water, air, fertilizers, and pesticides into the soil. Roots are normally quite shallow under thatch conditions, increasing the danger of drought damage to the plant. Disease attacks may be accentuated by thatch accumulations. Mechanical thatching equipment should be used in spring or fall when grass recovery is rapid. It is best to remove thatch accumulations in several treatments rather than at one time.

Tree/Bush Competition
Trees, especially those with shallow feeder roots, compete with grass for water, nutrients, and light. Where there is heavy shade and/or many surface roots, it is best to plant a ground cover such as pachysandra, myrtle, or ivy rather than attempt to grow grass. Where competition is less severe, improve turf by the following methods: (1) use shade-tolerant grasses such as the fescues. (2) fertilize grass at 1½ to 2 times the normal rate; (3) fertilize trees; (4) water deeply and infrequently; (5) maintain a soil pH favorable to the grass; (6) prune tree branches and roots as much as possible; and (7) mow the grass higher than normal.

As you can see there are are many lawn issues, many of which have similar symptoms but are very different in nature and treatment. Feel free to bookmark this page and come back to it as a reference to help you properly diagnose your lawn problems. We appreciate you checking out our blog.