Baking soda on your lawn is trending in France — but experts say it could backfire

French gardening websites are encouraging readers to try baking soda on their lawns this month. It's cheap, easy to find and already sitting in many kitchen cupboards. The idea is tempting, especially when green moss starts spreading across the grass after weeks of damp autumn weather.

But there's a catch. A treatment that appears to work on moss can also affect the grass around it. And if you don't deal with the reason moss keeps appearing, you could find yourself facing the same problem again next year.

So is baking soda really worth trying, or is there a better way to tackle a mossy lawn this autumn?

What baking soda does to moss

Baking soda can damage moss, which helps explain why the trick has become popular. French gardening guides suggest applying it either mixed with water or sprinkled directly onto affected areas.

But it can also harm the grass. Virginia Tech notes that baking soda and other household remedies may injure moss without reliably controlling it. These products are not approved moss treatments for lawns.

The bigger problem is that baking soda doesn't address why moss is growing there. Iowa State University explains that moss often appears where grass is thin or weak, usually because of shade, poor drainage or compacted soil. Raking moss out can help temporarily, but unless the conditions improve, it is likely to return.

So while baking soda may seem like a cheap shortcut, it risks damaging the grass without solving the underlying problem.

Why does moss keep coming back?

Moss often appears where grass struggles to grow. The usual causes include too much shade, damp soil, poor drainage and compacted ground.

Check whether trees or hedges block sunlight from reaching your lawn. Notice whether water collects in certain areas after rain. If people regularly walk over the same patch, the soil may have become compacted.

Cutting the grass too short can also leave it weaker and less able to compete with moss.

Unless you address these problems, removing the moss may only be a temporary fix.

What experts recommend doing in October

The UK's Royal Horticultural Society (RHS) recommends removing moss in October or early November, while the grass is still growing strongly enough to recover.

For a small lawn, use a spring-tined rake to pull out the moss. For a larger area, a mechanical scarifier can make the job easier. The process is called scarifying, and it also removes built-up dead material from the lawn.

The grass may look a little rough afterwards, but it can recover in suitable conditions. If the soil is compacted, aerating it can help improve drainage. You can also reseed bare patches to help the grass fill the gaps.

The RHS advises against using household products such as baking soda to kill lawn moss.

Should you use a mosskiller instead?

Some lawn products contain iron sulphate, which can kill moss. However, only use products approved for your location and follow the label carefully. In the Netherlands, you can check plant protection products through the government's guidance.

For most mossy lawns, start by removing the moss and looking at why it keeps returning. Baking soda may sound like an easy shortcut, but a healthier lawn depends on giving the grass better conditions to grow.