Sustainable Gardening

What is a blunting knife used for?

Multifunction tool

Contents

Modified the 21 September 2025 by Olivier 2 min. Difficulty: Débutant

A moss and weed knife is a rather specialised weeding tool. It’s a small garden implement whose steel head is set at a right angle and has several sharpened edges. Because this tool is very thin, it fits into tight spaces, notably between paving stones of a path or stones of a low wall. Why? To remove moss and adventive plants that sometimes grow there, of course! But that’s not all: the moss and weed knife can be used to weed in beds, vegetable boxes or planters and to hoe between plants.

Difficulty

What is a "couteau-émousseur"?

A weed knife is a gardening tool most often fitted with a short handle made of ash wood, plastic or composite materials and a steel head. It is therefore a hand-held gardening tool that requires working while crouched or is used for maintaining raised plantings such as vegetable beds or flower boxes.

The head is steel and has a rather special shape: it is a blade set at a right angle, almost like a duck’s beak. This “knife” has two sharpened edges: an outer edge on the right angle for precision work between slabs on a path or terrace, and an inner edge to cut herbs or scrape soil. De Pypere’s traditional weeding knife is a very good example. There are also versions with a long handle such as Spear & Jackson long-handle weeding knife.

weeding, weed removal, garden tool, hoeing, moss

Long-handle weeding knife

Weeding knives are used to :

Scrape soil to aerate it and weed flowerbeds : by scraping soil after watering or after rain, crusting is avoided. This allows better oxygenation of roots and also reduces watering;
Remove moss, clean and weed joints between paving slabs thanks to its fine, sharp edges.

please note : do not confuse “couteau-émousseur” and “démousseur” (or sometimes “émousseur”) which is a type of scarifier whose blades are replaced by tines. This tool is also called an “aerator”.

How to use a blunting knife?

To scrape soil: simply use the tip of the knife and scrape soil around plants with small movements;
To weed: use the knife to scrape into soil. It’s ideal for cutting the roots of young adventive plants in the soil or for detaching stolons of an invasive plant;
To remove moss and “weeds” between paving slabs or stones: in this case use the tip or the back of the knife (external right-angle) to pass between the slabs.

weed, weeding, garden tool, hoeing, moss