Can I Lay Turf Over Existing Lawn – The Real Risks And Better
We’ve all been there, staring at a patchy, weed-infested yard and wondering if there is a faster way to fix it. You might be asking, can i lay turf over existing lawn to save time and effort?
I understand the temptation to skip the grueling task of stripping old sod, but doing so could jeopardize your new grass before it even takes root.
In this guide, I will show you why preparation is the secret to a professional finish and how to ensure your new lawn thrives for years to come.
What's On the Page
- 1 The Short Answer: Can I Lay Turf Over Existing Lawn and Expect Success?
- 2 Why Laying New Turf Over Old Grass Often Fails
- 3 The Better Way: Preparing Your Soil for New Turf
- 4 The Compromise: When You Absolutely Must Lay Over Old Grass
- 5 Essential Tools for a Successful Turfing Project
- 6 Step-by-Step Guide to Laying Your New Turf
- 7 Crucial Aftercare: Helping Your New Lawn Take Root
- 8 Common Pitfalls to Avoid
- 9 Frequently Asked Questions About Laying Turf
- 10 Final Thoughts on Your Lawn Renovation
The Short Answer: Can I Lay Turf Over Existing Lawn and Expect Success?
The technical answer is yes, you can physically place new rolls of grass on top of old ones. However, as an experienced gardener, I must tell you that it is rarely a good idea for the health of your garden.
When you ask, can i lay turf over existing lawn, you are looking for a shortcut to a beautiful space. Unfortunately, this specific shortcut often leads to a phenomenon known as “turf failure” within just a few months.
The new roots need to penetrate deep into the soil to find moisture and nutrients. When they hit a layer of old, dying grass, they encounter a barrier that is difficult to cross.
Think of it like trying to grow a plant in a pot that still has the plastic lid on. The roots will struggle, the grass will turn yellow, and you may end up wasting a significant investment in new materials.
Why Laying New Turf Over Old Grass Often Fails
To understand why this method is risky, we have to look at what happens beneath the surface. When you place fresh turf over an existing lawn, you create a sandwich of organic matter that starts to rot.
As the old grass dies off, it begins to decompose. This process requires oxygen and releases heat, which can actually “cook” the delicate new roots of your fresh turf.
Furthermore, the old grass creates a thick layer of thatch. This thatch acts like a sponge, soaking up water before it can reach the actual soil, or worse, preventing the roots from ever reaching the earth.
Without a direct connection to the soil, your new lawn will be entirely dependent on you watering it multiple times a day. Even then, it will likely remain unstable and “squishy” underfoot for a long time.
The Problem of Air Pockets
Existing lawns are rarely perfectly flat. They have bumps, tufts of weeds, and small depressions that you might not notice until you try to lay something flat over them.
When you lay turf over these irregularities, you create air pockets. Roots cannot grow through thin air; they need constant contact with moist soil to survive and expand.
These pockets of air will cause the grass above them to dry out and die, leading to a “leopard print” pattern of brown spots across your brand-new lawn.
Nitrogen Depletion and Soil Health
The microorganisms that break down the old, buried grass require nitrogen to do their job. They will often “steal” this nitrogen from the surrounding soil.
This leaves your new turf starving for the very nutrients it needs to establish itself. You might notice the new grass looking pale or stunted shortly after the initial “honeymoon” period.
The Better Way: Preparing Your Soil for New Turf
If you want a lawn that looks like a golf green, you have to do the legwork. Many homeowners ask can i lay turf over existing lawn because they want to avoid the cost of a skip or the labor of digging.
However, spending a weekend on preparation will save you hundreds of dollars in replacement turf later. Here is the professional approach to getting it right the first time.
Step 1: Clearing the Area
Start by removing the old vegetation. You can use a manual spade for small areas, but for a standard garden, I highly recommend renting a turf cutter.
A turf cutter slices just under the root zone, allowing you to roll up the old grass like a carpet. This leaves you with a clean slate of bare soil that is ready for improvement.
If you have persistent weeds like dandelions or docks, you may want to apply a glyphosate-based weedkiller two weeks before you start digging to ensure the roots are dead.
Step 2: Relieving Soil Compaction
Once the old grass is gone, you’ll likely find that the soil underneath is hard and compacted. Roots need loose soil so they can spread out easily.
Use a garden fork or a powered rotovator to turn the soil to a depth of about 6 inches. This introduces oxygen and improves drainage, which is vital for preventing fungal diseases.
If your soil is heavy clay, this is the perfect time to mix in some sharp sand or organic compost to improve the structure and aeration.
The Compromise: When You Absolutely Must Lay Over Old Grass
While you can technically do it, asking can i lay turf over existing lawn usually leads to a discussion about soil health. However, if you are determined to try, there is a “modified” way to increase your chances.
I only recommend this if the existing “lawn” is actually just bare dirt with a few patches of thin grass. If you have a thick, lush lawn, you must remove it.
First, mow the existing grass as short as your mower will allow. This is often called “scalping” the lawn. You want to remove as much green material as possible.
Next, use a heavy-duty rake to scratch the surface of the soil deeply. This breaks up the thatch and creates “keying” points for the new roots to grab onto.
Adding a Layer of Topsoil
The secret to making this shortcut work is adding a substantial layer of high-quality topsoil over the old grass. You should aim for at least 1 to 2 inches of fresh soil.
This layer acts as a buffer. It provides a medium for the new roots to grow into while the old grass underneath slowly decomposes without suffocating the new arrivals.
Level this soil carefully using a wide landscaping rake. You want a firm, but not packed, surface that is perfectly smooth to avoid those dreaded air pockets.
Essential Tools for a Successful Turfing Project
Having the right tools makes the difference between a back-breaking chore and a satisfying weekend project. Don’t try to “wing it” with just a shovel!
- Turf Cutter: Essential for removing old grass quickly and evenly.
- Rotovator: For breaking up compacted soil and mixing in soil conditioners.
- Landscaping Rake: A wide rake is much better for leveling large areas than a standard garden rake.
- Lawn Roller: Used to firm the soil before laying and to press the turf down afterward.
- Sharp Knife or Edging Iron: For trimming the turf rolls to fit around flower beds and paths.
If you don’t own these, check your local tool hire shop. Renting a professional-grade rotovator for a day is much cheaper than buying one and will save you hours of manual labor.
Step-by-Step Guide to Laying Your New Turf
Once your soil is prepared, leveled, and firmed, it’s time for the fun part. Laying turf is like putting together a giant, living puzzle.
- Start at the edge: Begin at the furthest straight edge of your garden. Avoid walking on the newly prepared soil as much as possible.
- Stagger the joints: Lay the turf in a brickwork pattern. This prevents long seams where water can run off and cause erosion.
- Butt the edges tightly: Ensure the edges of the rolls are touching but not overlapping. You don’t want any gaps where weeds can poke through.
- Use boards: Always stand on wooden planks or “crawling boards” while laying. This distributes your weight and prevents you from leaving deep footprints in the fresh soil.
- Tamp it down: Once finished, use the back of a rake or a light roller to ensure the turf has good contact with the soil.
Remember, turf is a living product. You should aim to lay it within 24 hours of delivery, especially in the summer, or it will begin to yellow and ferment in the rolls.
Crucial Aftercare: Helping Your New Lawn Take Root
The first two weeks are the most critical period for your new lawn. Even if you did everything right, a lack of water at this stage will be fatal.
In summary, can i lay turf over existing lawn is a question of short-term ease versus long-term durability. If you choose the shortcut, your aftercare must be even more rigorous.
Water the lawn immediately after laying. You want the water to soak through the turf and into the soil beneath. Lift a corner of a roll to check—the soil underneath should be damp.
During the first week, water every morning and evening unless there is heavy rain. If the weather is hot and windy, you might even need a third soaking in the afternoon.
When to Mow for the First Time
Be patient! Do not rush out with the mower as soon as the grass looks long. You need to wait until the roots have firmly anchored themselves into the soil.
To check this, gently try to lift a corner of the turf. If you feel resistance, the roots are doing their job. This usually takes about 2 to 3 weeks.
For the first mow, set your blades to the highest possible setting. You only want to take the very tips off the grass. Never remove more than one-third of the blade height at once.
Common Pitfalls to Avoid
Even experienced gardeners make mistakes. Here are a few things to watch out for to ensure your lawn stays green and healthy.
Walking on the lawn too soon: Keep pets and children off the new grass for at least three weeks. Foot traffic can compress the soil and tear the fragile new root hairs.
Under-watering the edges: The edges of the turfed area and the seams between rolls dry out much faster than the center. Pay extra attention to these spots during your watering routine.
Over-fertilizing: Most high-quality turf comes pre-fertilized from the grower. Adding more “starter fertilizer” immediately can actually burn the new roots. Wait at least 6-8 weeks before feeding.
Frequently Asked Questions About Laying Turf
Can I lay turf in the winter?
Yes, you can lay turf in winter as long as the ground isn’t frozen or waterlogged. In fact, turf stays fresh much longer in cold weather. However, the roots will grow much slower, so you won’t be able to walk on it for a longer period.
How long does it take for turf to root?
In the peak growing seasons of spring and autumn, you can expect the turf to root within 10 to 14 days. In the height of summer or the middle of winter, this process can take 3 to 5 weeks.
Should I put sand under my turf?
A thin layer of sharp sand can help with leveling and drainage, especially on clay soils. However, don’t use builders’ sand, as it contains salts and fine particles that can actually block drainage and harm the grass.
What happens if I don’t remove the weeds first?
If you don’t remove or kill weeds before laying turf, they will likely grow through the seams of your new lawn. Perennial weeds like thistles are strong enough to push right through the turf itself, ruining the uniform look of your new grass.
Final Thoughts on Your Lawn Renovation
Creating a beautiful garden is a journey, and while it’s tempting to look for the fastest route, the “right” way is always more rewarding. While you might still be wondering, can i lay turf over existing lawn, I hope this guide has shown you that the extra effort of clearing the ground is worth it.
By removing the old grass, tilling the soil, and ensuring proper contact, you are giving your new lawn the best possible start in life. Your garden will be more resilient to drought, more resistant to disease, and much more beautiful to look at.
Don’t be afraid to get your hands dirty! Grab a spade, rent that turf cutter, and start building the lawn of your dreams today. You’ve got this, and your future self will thank you every time you step out onto that lush, soft carpet of green. Go forth and grow!
