Why is My Grass Turning Black in Spots?

Seeing black spots appear on your otherwise green lawn can be alarming The sudden change in color is unsightly and can signify deeper issues with the health of your grass But what causes grass to turn black in patches? And what can you do to restore your lawn’s vibrancy?

There are a few common culprits behind black spots on lawns Identifying the specific cause will allow you to take targeted action to treat the problem With some care and intervention, you can get your grass looking lush and uniform again.

What Causes Black Spots on Grass?

There are several potential explanations for grass transforming from green to black in localized areas

Fungal Diseases

Different types of fungal infections can lead to black spots on grass. Common culprits include:

• Leaf spot disease: Causes small, round black spots surrounded by yellowing on grass blades. It thrives in wet, humid, and warm conditions.

• Pythium blight: Causes irregular black spots that can expand rapidly in size. It is prevalent in hot, wet weather.

• Leaf smuts: Cause elongated black powdery spores on grass leaves. They occur more often in the shade.

• Slime molds: Cause black dotting or mottling from colonies of microscopic organisms. They peak after heavy rainfall.

Fungal diseases disrupt the grass plant’s vascular system and stunt its growth. The black spots are where tissue has died. If left untreated, the fungi can spread to kill entire sections of lawn.

Insect Damage

Some lawn pests feed on and damage grass plants, causing black spots to form. Common culprits include:

• Chinch bugs: Cause yellowing that progresses to browning and black patches during hot, dry weather. The pests suck fluids from grass stems and blades.

• Grubs: These larvae chew on grass roots, which leads to drying and black spots. Damage is most severe in late summer and early fall.

• Armyworms: Feed on grass blades, creating areas of blackened, severed shoots. Outbreaks often follow periods of heavy rain.

Controlling the insect population and treating damaged areas can help restore your lawn’s health and color.

Environmental Stress

Environmental factors can also turn patches of grass black:

• Drought: Insufficient water leads to drying and browning as grass plants become severely dehydrated.

• Excess moisture: Overwatering causes root rot and invites fungal growth, resulting in dieback.

• Compacted soil: When soil is too dense, air and water can’t penetrate to roots and grass dies. This often occurs in high traffic areas.

• Shade: Grass starved of sunlight due to overhanging trees or buildings can thin out and turn black.

• Pet urine: Urine contains high nitrogen that burns grass when concentrated in one area.

• Chemical damage: Overapplying fertilizer or weed killers can damage grass and create spots.

Relieving adverse environmental conditions will allow your lawn to recover and re-establish in affected areas.

How to Treat Black Spots in Grass

The specific treatment will depend on the underlying cause. But in general:

Maintain Optimal Growing Conditions

• Water deeply 1-2 times a week during dry periods to keep soil moist but not saturated.
• Avoid over-fertilizing which can burn grass.
• Improve drainage in any areas prone to waterlogging.
• Reduce shade by pruning overhanging trees and shrubs.

Treat Disease Outbreaks

• Have any black spots tested at a garden center to identify the fungal disease.
• Apply appropriate fungicide per product instructions.
• Remove and dispose of severely infected grass.
• Avoid over-watering and improve drainage.

Get Rid of Lawn Pests

• Apply insecticidal soap, neem oil, or other natural pest control for bugs.
• Use grub control treatments to kill larvae.
• Remove armyworms manually if infestation is light.
• Keep grass height 3+ inches tall to deter pests.

Reseed Affected Areas

• Scratch up dead patches with a rake to allow for root access.
• Fill in bare spots by overseeding with similar grass variety.
• Cover newly seeded areas with straw to retain moisture.
• Water daily for 2-3 weeks until new grass is established.

How to Prevent Black Spots on Grass

An ounce of prevention is worth a pound of cure when it comes to black lawn spots. Here are some proactive measures to keep your grass healthy and thriving:

• Mow high (3-4 inches) to encourage deep root growth.
• Aerate compacted areas in spring or fall.
• Dethatch to prevent fungal growth in thick turf.
• Allow grass to dry between waterings.
• Apply corn gluten meal in spring to deter pests.
• Keep fertilizing and chemical use to minimum effective levels.
• Check for early signs of lawn disease like mushroom circles.
• Reseed thin or bare patches as soon as they appear.

By maintaining optimal growing conditions and addressing issues promptly, you can avoid many common causes of black spots. Healthy, vigorous grass is less susceptible to damage.

When to Call a Lawn Care Professional

For widespread or recurring black spot issues, it may be time to consult a professional:

• If over 25% of the lawn is affected or problems persist despite treatment.
• If the cause is unclear and black spots keep returning.
• For testing and diagnosis of suspected fungal diseases.
• If thatch buildup or heavy insect infestation needs addressing.
• For hydroseeding or resodding large dead sections.

Lawn care pros have specialized expertise, equipment, and products that may be needed for stubborn black spot problems. Their services will get your grass growing green and healthy again.

Give Your Lawn Some TLC

While black spots can detract from your lawn’s beauty temporarily, a bit of dedicated care and attention can get it looking lush again. Consistent maintenance and prompt treatment when problems arise will keep your grass thriving for years to come. Pay attention to trouble spots and don’t be afraid to call in the pros when needed. With some TLC, you can eliminate black patches for good.

To eliminate black mold from your lawn, you can either use natural solutions like baking soda and vinegar or opt for chemical treatments like fungicides.