Five Common Lawn Care Mistakes

Unfortunately, knowledge isn’t hereditary. We learn as we go, this is especially true when it comes to lawn care. Every first-time homeowner has to go through the same basic steps to learn how to care for their lawn. Should I set my lawn mower to a specific cutting height? How much water should I use? When is the best time to fertilise my lawn? These are just a few of the numerous questions that arise. The Lawn Institute offers these suggestions so you can avoid a few of the basic mistakes people make when it comes to proper lawn care.

1. Mowing

An unsharpened lawnmower blade will actually rip or tear the grass leaves rather than provide a clean even cut. The ripping or tearing of the plant tissue can create a breeding ground for disease and other problems. Cutting your lawn too short is another common mistake that can create an environment that encourages weed growth, increases heat stress during dry or hot periods and makes your lawn more susceptible to insects and disease.

Recommendation

Always keep your lawnmower blades sharp. At the outset of each growing season, sharpen the blades or have your blades sharpened by a professional. If you live in a warmer climate, where lawn care is a year-round activity, check your lawnmower blades periodically to make sure they’re sharp.

Best Practices

• Set your mower blade to cut no more than the top third of the grass plant
• Encourage stronger root growth
• Avoid cutting too short to prevent moisture loss, weeds, and disease

2. Watering

Water is essential to all life. Too little water leads to drying out, while too much causes damage. The same is true for lawn care. Water makes up 70% to 80% of lawn grass weight, and clippings are nearly 90% water. Despite common concerns, more lawns are damaged by overwatering than underwatering.

Recommendation

Use water wisely and practice conservation. Proper watering is critical, especially for new lawns.

For New Lawns

• Apply at least 1 inch (2.5 cm) of water within 30 minutes of installation
• Water daily (or more often) for about 2 weeks
• Keep soil consistently moist until roots establish

For Established Lawns

• Average requirement: about 1 inch per week
• Adjust based on grass type, soil, and season

Signs Your Lawn Needs Water

• Grey-blue grass color
• Footprints remain visible after 30 minutes
• Soil is hard to penetrate with a probe

Additional Tips

• Brown grass during drought may be dormant—not dead
• Most grasses survive 30–60 days without water

3. Fertilising

Common fertilising mistakes include using the wrong type, applying too much, or fertilising at the wrong time. Over-fertilising can increase thatch, attract pests, and even burn your lawn.

Recommendation

Aim for balanced growth—healthy leaves and strong roots.

Understanding Fertiliser (N-P-K)

• Nitrogen (N): Promotes green color and leaf growth
• Phosphorus (P): Supports energy transfer and root development
• Potassium (K): Enhances stress resistance and plant strength

Choosing the Right Fertilizer

• Use slow-release nitrogen forms
• Ideal ratios: 3-1-2 or 4-1-2
• Examples: 12-4-8, 15-5-10, 16-4-8

Application Guidelines

• Use minimal effective amounts
• 8 lbs per 1,000 sq ft for low nitrogen fertilisers
• 4 lbs per 1,000 sq ft for high nitrogen fertilisers
• Always follow label instructions

When to Fertilise

• Fertilise during active growth periods
• Cool-season grasses: spring and fall
• Warm-season grasses: late spring and summer

Important Tip

• Leave grass clippings on the lawn (grasscycling)
• Reduces fertiliser needs by up to 25%
• Environmentally friendly

4. Dethatching

Thatch is a layer of dead and living plant material between grass and soil. While some thatch is beneficial, too much can harm your lawn.

Recommendation

Only dethatch when necessary and use proper equipment.

How to Check for Thatch

• Remove a small plug of turf
• Measure the spongy layer
• If thicker than ¾–1 inch, dethatching is needed

Best Practices

• Use vertical mowers or dethatchers
• Avoid removing all thatch at once
• Do not dethatch wet soil
• Perform during late summer or fall

After Dethatching

• Remove and compost debris
• Grass clippings do NOT contribute to thatch

5. Aeration

Aeration helps relieve soil compaction and allows water, air, and nutrients to reach grass roots.

Recommendation

Use core aeration to improve lawn health.

How Aeration Works

• Removes soil plugs 2–3 inches deep
• Spaces holes about 3 inches apart
• Improves airflow and nutrient absorption

Best Practices

• Water lawn lightly the day before
• Avoid overly wet soil
• Make two passes if needed (crisscross pattern)
• Mark sprinkler heads before starting

When to Aerate

• Cool-season grasses: Fall
• Warm-season grasses: Late spring or summer

After Aeration

• Leave soil plugs on the lawn
• They will decompose and return nutrients