Converting a grassy lawn into a garden bed begins with smothering the sod rather than tilling it. If you’re wondering how to start a garden where grass is currently, the key is to work with the grass, not against it. This method saves time, preserves soil health, and prevents weeds from taking over your new garden.
Starting a garden in a grassy area might seem daunting, but it’s simpler than you think. You don’t need heavy machinery or chemicals. Just a bit of planning and patience.
In this guide, I’ll walk you through every step. From killing the grass to planting your first seeds. You’ll learn the no-till method, which is gentle on your back and the environment.
Let’s get started.
Why Smothering Grass Works Better Than Tilling
Tilling breaks up the soil and mixes grass into it. Sounds good, right? Not really. Tilling brings buried weed seeds to the surface. It also disturbs beneficial soil organisms like worms and microbes.
Smothering kills the grass by blocking sunlight. The grass dies naturally, roots and all. The organic matter stays in place, feeding the soil as it decomposes.
This method is called “lasagna gardening” or sheet mulching. It’s perfect for beginners because it requires minimal effort.
What You’ll Need For The Smothering Method
- Cardboard (large sheets, remove tape and staples)
- Compost or topsoil
- Mulch (straw, wood chips, or leaves)
- Water source
- Garden hose or sprinkler
That’s it. No fancy tools. No expensive equipment.
How To Start A Garden Where Grass Is Currently
Now let’s get into the step-by-step process. Follow these steps carefully, and you’ll have a thriving garden bed in no time.
Step 1: Mow The Grass As Low As Possible
Start by mowing your lawn very short. Set your mower to the lowest setting. The shorter the grass, the easier it is to smother.
Leave the clippings on the ground. They add organic matter. Don’t bag them.
Water the area thoroughly. Wet grass decomposes faster. It also helps the cardboard stick to the ground.
Step 2: Lay Down Cardboard
Get large pieces of corrugated cardboard. Avoid shiny or colored cardboard. Plain brown is best.
Overlap the edges by at least 6 inches. This prevents grass from sneaking through gaps. Cover the entire area you want to turn into a garden.
Wet the cardboard thoroughly with a hose. This helps it conform to the ground and stay in place.
Cardboard blocks light, so the grass underneath dies within a few weeks. It also attracts earthworms, which will help aerate your soil.
Step 3: Add A Layer Of Compost
Spread 2 to 3 inches of compost on top of the cardboard. This provides nutrients for your plants. It also weighs down the cardboard.
Use high-quality compost from a garden center or your own pile. If you don’t have compost, use topsoil mixed with aged manure.
Water this layer lightly. You want it moist, not soaking wet.
Step 4: Add Mulch
Cover the compost with 3 to 4 inches of mulch. Straw, wood chips, or shredded leaves work well. Mulch retains moisture, suppresses weeds, and looks tidy.
Straw is ideal for vegetable gardens. Wood chips are better for pathways or perennial beds.
Water the mulch layer again. This settles everything and starts the decomposition process.
Step 5: Wait And Let It Work
Now you wait. The grass will die under the cardboard. This takes about 4 to 6 weeks in warm weather. In cooler climates, it may take longer.
Check progress by lifting a corner of the cardboard. The grass should be yellow or brown and easy to pull up. If it’s still green, give it more time.
During this waiting period, you can plan your garden layout. Decide what to plant and where.
Alternative Methods For Starting A Garden In Grass
Smothering isn’t the only way. Here are other methods you can try, depending on your timeline and preferences.
Method 1: Solarization
Solarization uses the sun’s heat to kill grass. Cover the area with clear plastic for 4 to 6 weeks during hot summer months. The heat builds up under the plastic, cooking the grass and weed seeds.
This method works best in sunny areas. It’s not effective in shade or cool weather.
Method 2: Double Digging
Double digging is more labor-intensive. You remove the top layer of sod, dig a trench, and then loosen the soil below. It’s good for small areas but hard on your back.
I don’t recommend this for large gardens. Stick with smothering if you can.
Method 3: Chemical Herbicides
Some people use glyphosate-based herbicides to kill grass. This is fast but harmful to soil life and beneficial insects. I strongly advise against it.
Organic methods are safer and more sustainable. They also build healthy soil over time.
Preparing The Soil After The Grass Dies
Once the grass is dead, you can start planting. But first, check your soil quality.
Dig a small hole and look at the soil. Is it dark and crumbly? Or is it hard and clay-like? Most lawn soil is compacted and low in organic matter.
Here’s how to improve it:
- Add 2 inches of compost each year
- Use cover crops like clover or rye in the off-season
- Avoid walking on the soil to prevent compaction
- Mulch heavily to retain moisture
You don’t need to till. The worms and roots will do the work for you.
Testing Soil PH
Soil pH affects nutrient availability. Most vegetables prefer a pH between 6.0 and 7.0. You can buy a simple test kit at a garden center.
If your pH is too low (acidic), add lime. If it’s too high (alkaline), add sulfur. Follow package instructions.
Testing in fall gives you time to adjust before spring planting.
What To Plant In Your New Garden
Now the fun part. Choose plants that suit your climate and sunlight.
If your garden gets full sun (6+ hours daily), try:
- Tomatoes
- Peppers
- Zucchini
- Basil
- Sunflowers
If you have partial shade (3-6 hours), go with:
- Lettuce
- Spinach
- Kale
- Mint
- Ferns
Start small. A 4×4 foot bed is plenty for a beginner. You can always expand next year.
Planting Directly Into The Mulch
You can plant seeds or seedlings directly into the compost layer. Just pull back the mulch, make a small hole, and plant. Cover with compost and water well.
For seeds, follow the depth instructions on the packet. Most seeds need to be covered with soil about twice their diameter.
Water gently to avoid washing seeds away. Use a watering can with a rose attachment.
Maintaining Your No-Till Garden
Once your garden is growing, maintenance is simple.
Watering
Water deeply once or twice a week, depending on weather. Mulch helps retain moisture, so you’ll water less often than a bare soil garden.
Check soil moisture by sticking your finger 2 inches deep. If it’s dry, water. If it’s moist, wait.
Weeding
Weeds will still appear, but fewer than in a tilled garden. Pull them by hand when they’re small. The cardboard barrier prevents most perennial weeds.
If grass tries to grow back along the edges, add more cardboard or mulch.
Fertilizing
Add compost as a top dressing each spring. You can also use liquid fertilizers like fish emulsion or seaweed extract every few weeks.
Avoid synthetic fertilizers. They can harm soil life and leach into waterways.
Seasonal Care
In fall, add a thick layer of leaves or straw. This protects the soil over winter and feeds worms.
In spring, pull back some mulch to let the soil warm up. Then add fresh compost and plant.
Common Mistakes To Avoid
Even with the best method, things can go wrong. Here are mistakes to watch for.
Using Thin Cardboard
Thin cardboard like cereal boxes breaks down too fast. Use thick, corrugated cardboard from shipping boxes. It lasts longer and blocks light better.
Skipping The Watering Step
Dry cardboard won’t stay in place. It also decomposes slowly. Water each layer as you build it.
Planting Too Soon
If the grass isn’t fully dead, it will regrow and compete with your plants. Wait until the grass is clearly dead before planting.
Ignoring Soil Compaction
Even with no-till, soil can become compacted if you walk on it. Use paths or stepping stones to avoid stepping on the bed.
Frequently Asked Questions
Can I start a garden in grass without killing the grass first?
No, you must kill the grass first. If you plant directly into grass, it will compete for water and nutrients. The smothering method is the easiest way to kill it.
How long does it take to start a garden where grass is currently?
Using the smothering method, you can plant in 4 to 6 weeks. The grass dies quickly under cardboard. You can speed things up by using thick layers of cardboard and keeping it moist.
Do I need to remove the grass roots?
No, the roots will decompose naturally. They add organic matter to the soil. This is one of the benefits of the no-till method.
Can I use newspaper instead of cardboard?
Yes, but use several layers (at least 8-10 sheets thick). Newspaper breaks down faster than cardboard, so it may not last as long. Cardboard is more reliable.
What if I have Bermuda grass or other aggressive types?
Bermuda grass is tough. You may need to use thicker cardboard and wait longer. Some people add a layer of plastic on top of the cardboard for extra smothering. Be patient and check regularly.
Final Thoughts On Starting A Garden In Grass
Starting a garden where grass currently grows is a rewarding project. The smothering method is simple, effective, and good for the environment.
You don’t need to be an expert. Just follow the steps: mow low, lay cardboard, add compost and mulch, and wait. Then plant what you love.
Your soil will improve each year. Your garden will thrive. And you’ll have fresh food or beautiful flowers right outside your door.
So grab some cardboard and get started. Your new garden is waiting.