Learn which plants thrive in your Hardiness Zone with our new interactive map!

The Cardboard Method of Weed Killing

By Jenny Harrington ; Updated September 21, 2017
Recycle old boxes into weed-control mulch.
cardboard box image by MAXFX from Fotolia.com

Weed control is a constant battle in many home gardens. Getting rid of weeds in a new or overgrown bed may seem like more effort than it's worth, but there are ways to simplify the process. Standard mulches prevent some weed growth, as the weed seeds cannot access the light they need to germinate. A cardboard mulch is an inexpensive way to kill out the weeds in a large area. Since cardboard is too thick for many weed plants to penetrate, it also helps choke out any existing weeds, as well as preventing seed germination.

Break down cardboard boxes so they lay flat. Cover the bed with the cardboard sheets, overlapping the edges by 5 inches so weeds can't grow between the seams.

Water the cardboard until it is thoroughly soaked.

Cover the cardboard with 8 inches of straw mulch or wood chips. The additional mulch layer prevents any weeds that do penetrate the cardboard from reaching maturity. Allow the mulch to settle for one week.

Cut holes through the cardboard and plant your seedlings in the holes. Alternatively, apply the cardboard the year before planting so most of the weeds are completely killed by the spring planting season.


Things You Will Need

  • Cardboard
  • Mulch


  • Substitute newspaper for cardboard. Apply a 10- to 12-sheet layer of newspaper, then cover it with the mulch.
  • Use the cardboard method on existing perennial beds. Lay the cardboard sheets around the existing plants then cover with enough mulch to camouflage the cardboard.


  • Some grasses may still penetrate the cardboard. Pull these immediately so they do not compromise the effectiveness of the cardboard against other weeds.

About the Author


Jenny Harrington has been a freelance writer since 2006. Her published articles have appeared in various print and online publications. Previously, she owned her own business, selling handmade items online, wholesale and at crafts fairs. Harrington's specialties include small business information, crafting, decorating and gardening.