Summer is rough on grass. After a few straight months of heat, sun, foot traffic, and often not enough rain, it’s totally normal to see some dead spots. Dead grass is uglier than it is dangerous, but if you’re sick of looking at it, here’s a quick and dirty guide to replanting grass where it’s needed.
Figure out what kind of grass you have
Different grass species thrive under different conditions, which means the very first thing you need to do is identify the type (or types) of grass you’re dealing with. This will make important decisions — like when to plant, which seed to buy, and which fertiliser to use — much more straightforward.
In general, you want to plant new grass when it’s cool, but not cold. For most areas, that means either early autumn or early spring; the exact window depends on your location and which species you’re working with.
Break up the dead stuff
Scattered dead spots can happen for several reasons, but one of the most common culprits is thatch — an overly thick layer of dead grass, roots, and other organic matter that lies between the grass roots and the soil. Normal thatch acts like compost, but if it gets too thick and/or compacted, it cuts off the supply of soil nutrients and water that grass needs to grow.
That means you have to physically break it up. “Dethatching” an entire lawn requires buying or renting a gas- or electric-powered lawn dethatcher, but for small spots, all you need is a handheld cultivator tool. A simple claw cultivator (which is basically a mini rake with sharp, hefty tines) will do in a pinch; for larger projects, you may consider investing in a rotary cultivator. These tools work a bit like push mowers, but with tines instead of blades, and cost somewhere between $40-70. The rotating tines easily break up tough thatch and aerate the soil so your seed can take root.
For a visual guide to dethatching dead spots check out this video from The Lawn Whisperer YouTube channel:
Plant (and fertilize) some seeds
Once you’ve broken up all the thatch, it’s time to plant some seeds. Grass seeds do best when scattered in an even layer across the soil; if you look closely, the area should be about 50% seed and 50% dirt. In the video above, The Lawn Whisperer suggests gently running your cultivator tool over the seeded area to help work them in a bit.
Next, you’ll want to fertilize the seed. You can use any kind of fertiliser that’s indicated for “starter lawns” — these varieties have a high phosphorus content, which encourages root growth. Liquid or granulated fertiliser can both work, but there are pros and cons to each type. The Home Depot website has a helpful guide to lawn fertilisers, and you can find location-specific recommendations through your state university’s extension program.
Keep it watered — and be patient
Grass needs a lot of water to grow, so you’ll have to keep your new seedlings nice and moist — but not drenched. To do this, lawn care company Scotts recommends misting freshly planted seed at least twice a day, then switching to slightly heavier watering once it germinates.
Finally, patience is key. Resist the urge to mow your new grass until it’s at least a couple of inches tall. If you mow too soon, you’ll just rip out the root network you worked so hard to establish. This can take several weeks or even longer, depending on your soil and what kind of grass you’re working with, but it will happen eventually. Just keep at it: With regular watering and a little help from the fertiliser, your grass will grow back.