Gardener’s tip for £1: Use bath additive for a lush green lawn before summer.

In gardening forums and across social media, a supposedly simple lawn hack keeps cropping up-one that sounds almost too good to be credible. Instead of paying for pricey specialist fertilisers, some home gardeners are sprinkling a cheap product from the bath section over their grass, often costing around £1. There is no secret “miracle cure” at work here; it is a long‑established mineral salt that can correct one very specific deficiency in soil.

What this low-cost bath additive is really doing for your lawn

The much‑talked‑about tip centres on Epsom salt, chemically magnesium sulphate. It comes as a crystalline salt and is commonly sold in chemists and supermarkets for relaxing foot baths or full baths. The same ingredient also appears in garden centres as a component in fertilisers.

Epsom salt (magnesium sulphate) and magnesium: why they matter to chlorophyll in grass

Magnesium plays a crucial part in plant health because it sits at the heart of the chlorophyll molecule-the green pigment in leaves. If grass does not have enough magnesium available, it cannot use light energy as effectively. The result can be slower growth and a washed‑out or yellowish appearance. This is exactly where the trend comes from: when there is a genuine magnesium shortfall, topping it up can help get growth moving again.

Magnesium is a bit like the engine of leaf green-when there isn’t enough in the soil, the lawn often shows it quite clearly.

Gardeners who use Epsom salt on weakened patches report the following effect:

• faster greening-up after winter

When the “£1 fix” makes sense-and when it doesn’t

Because Epsom salt is magnesium sulphate, it is best understood as a targeted way to address a magnesium deficiency, not as an all‑round lawn feed. If the grass is struggling for other reasons-such as compacted soil, drought stress, poor drainage, heavy shade, or lack of nitrogen-adding magnesium alone will not solve the underlying problem.

A practical way to keep expectations realistic is to treat Epsom salt as a corrective tool: it can help where magnesium is the limiting factor, but it is not a substitute for broader lawn care such as proper mowing height, adequate watering in dry spells, and regular aeration where the ground has become compacted.