Ron Hazelton

How to Fix Brown Spots in Your Lawn

Lawn & Garden

HOUSE DOCTOR Transcript

HD021 “LAWN TIPS” from episode 616

RON:

Here's Kathleen Brenzel, Senior Editor of Sunset Magazine, with some gardening tips.

KATHLEEN:

If you have a lawn, you know that there are times when brown spots are going to develop. Usually, thatch is the cause. When thatch builds up, and thatch is this straw-like accumulation of plant parts that makes a matte so thick over your lawn soil that it chokes off moisture and nutrients, and they just can't get down to the plant roots. When that builds up, you can take action. What you need to do is patch your lawn.

I'll show you how.

The first thing you have to do is get rid of that thatch and loosen the soil. And to do that, I like to use a thatching rake. And that's this sharp-tined rake that has very sharp points on both sides. And you run it back and forth across the soil. And that cuts up the thatch and loosens the soil at the same time.

After you have the soil good and broken up, and that thatch nice and cut and carted away, then you can scatter the grass seed. Now, I've chosen a turf-type tall fescue, and I've mixed it with time-release fertilizer. This is a good deep-rooted grass that's very suited to the west, but you can use a Kentucky bluegrass in cooler areas.

Now, seeding is one way to patch a lawn. You can also use sod. But the nice thing about seed is it's inexpensive, and it's fairly easy.

The next thing is to cover those seeds with a thin layer of organic mulch. And I'm putting compost on there. And you just want it to be about a quarter of an inch thick, just enough to cover the seeds and the fertilizer. Then I'm going to walk on the place that I patched, walk on that soil so that you can press the seeds and the fertilizer down into the soil.

Now, in order to keep that seed on the ground where you want it growing, rather than serving dinner for the birds, you need to cover it with bird netting. This is a plastic netting, very fine mesh, that you can buy by the roll at nurseries. And get a piece that's big enough to cover your patch.

Now, to keep that bird netting elevated so that the birds can't peck through it to get the seed, I've put stakes on all four sides of the patch. And I'm going to elevate the netting up over it.

And finally, to get these seeds started, I'm going to mist them with a fine spray of water, just to get them started. Now, one thing you want to remember is to keep these watered until the seedlings come up. Let them grow on. Don't even try to mow your lawn until it's at least two and a half inches tall.

Well, with just some careful patching like this, you can have a beautiful lawn again.

HouseCall’s Lawn Patching Guide

Thatch buildup is killing your grass. Ron explores how to diagnose the problem and bring back a lush, healthy lawn in a weekend.

If you've noticed dry, dead patches spreading across your lawn, you're not alone — and it’s not always a watering problem. More often than not, the culprit is thatch: a dense, straw-like mat of decomposed plant material that accumulates between the grass blades and the soil. When thatch gets too thick, it blocks moisture and nutrients from reaching the roots, and your grass starts to suffocate from below.

What is thatch — and why does it cause brown spots?

Thatch forms naturally as grass produces more organic matter than soil microbes can break down. A thin layer (under ½ inch) is actually beneficial, acting as a natural mulch. But when it builds up beyond that, it forms a tight barrier. Water rolls off instead of soaking in. Fertilizer sits on the surface instead of reaching roots. The result is a brown, thinning turf that looks drought-stressed even after rain.

To tell if you have a thatched area, poke a screwdriver into a brown patch. If it hits a spongy, fibrous layer before reaching soil, thatch is the problem. If it slides into the soil with ease, then investigate other problems such as irrigation or grub damage.

The 6-step lawn patching process

Follow these steps for each bare or brown patch in your yard.

STEP - 1

Dethatch the area

Use a thatching rake — a sharp-tined tool with pointed teeth on both sides — to cut through the thatch and loosen compacted soil simultaneously.

STEP - 2 - Remove Debris

Rake up and discard the loosened thatch. Don't compost it — thatch can reintroduce the same compaction problem.

STEP - 3 - Seed the Patch

Scatter your chosen grass seed evenly across the loosened soil. Mix with a time-release fertilizer for best early growth results.

STEP - 4 - Apply Organic Mulch

Spread a thin layer of compost — just ¼ inch deep — over the seed to retain moisture and protect germination.

STEP - 5 - Press Seeds In

Walk firmly across the patch to press seeds and fertilizer into soil contact. Good seed-to-soil contact is critical for germination.

STEP - 6 - Protect & Water

Cover with fine-mesh bird netting elevated on stakes. Mist daily and keep moist until seedlings emerge and reach 2½ inches tall.

Choosing the right grass seed for your region

Not all grass seed performs equally in every climate. Picking the wrong variety is one of the most common lawn patching mistakes.

Seed vs. sod: which should you use?

Both work — the right choice depends on your budget and timeline. Seed is inexpensive and widely available, making it ideal for DIY patching. The tradeoff is time: grass seed takes 2–4 weeks to germinate and several months to fully establish. Sod offers instant results but costs significantly more per square foot and requires careful installation to prevent air gaps under the turf.

For most small-to-medium brown patches (under 4 square feet), seed with a time-release fertilizer is the practical, budget-friendly choice.

A common mistake is mowing too soon. Wait until seedlings reach at least 2.5 inches tall before the first cut. Mowing too early pulls seedlings out of the soil before roots can anchor.

Frequently asked questions

How often should I water after seeding?

Keep the seeded area consistently moist — light misting once or twice daily works well. Avoid heavy watering that washes seeds away. Once seedlings emerge, water deeply but less frequently to encourage deep root growth.

Why do I need bird netting?

Freshly scattered grass seed is an easy meal for birds. Fine-mesh plastic bird netting, elevated on small stakes above the patch, keeps birds from pecking through while still allowing light and water to reach the seeds.

Can I use regular compost as mulch?

Yes — standard garden compost works well as a seed-covering mulch. Apply no more than ¼ inch. Thicker layers can prevent light from reaching germinating seeds and slow establishment.

What if my entire lawn has thatch problems?

For widespread thatch, consider renting a power dethatcher or vertical mower, which covers large areas much faster than a hand rake. Late summer and early fall are the best times to dethatch cool-season grasses; early summer for warm-season varieties.

Tools you'll need for this project

Thatching rake · Grass seed (regional variety) · Time-release fertilizer · Garden compost · Bird netting · Stakes · Garden hose with mist nozzle