Weeds in sidewalk cracks

From the whetstone · October 2026

Sidewalk cracks and paver joints are the hardest places in a garden to weed and the easiest to ignore. A corrugated Japanese crack weeder cuts weeds at the root inside the joint. Here is the routine that keeps paths clean.

Nisaku crack weeder clearing weeds between paving

Why crack weeds come back

Weeds in cracks root into the sand and soil under the paving. Pulling the leaves leaves the root, and the weed regrows within weeks. A crack weeder cuts the plant below the surface, inside the joint, which weakens it each time.

The routine

Water the cracks the evening before so roots let go
Run the weeder along the joint, not across it
Go over each crack twice: once to cut, once to pull out the clippings
Sweep the joints clean so seeds have less soil to land in
Repeat every three or four weeks in the growing season

Which crack weeder?

For steps and short joints, a hand-held weeder: the NJP2500 zassou tawashi scrubs like a brush, the NJP2510 has a curved blade, the NJP2511 an angled point for hairline cracks. For patios, the NJP2516 medium handle weeder. For long driveways, the Weed Brush PRO No. 2516 M with its two-hand handle.

Blades wear; replace them

Concrete is abrasive. The Pro weeders take NJP2517 replacement blades, three per pack. Swap a blade when it starts tearing weeds instead of cutting them.