Using Cardboard as Weed Barrier

 

The picture above shows what my corn patch looks like at the moment.

This year is my first experience with using cardboard as weed barrier. Here I thought that I was the first one to come up with this idea but after doing some research it turns out that this is not an unusual thing to do. So far it seems to be working out well. Since this is new to me, I did do a lot of reading up on it to make sure I'd know what I was getting myself into. 

Here are a few hints:

- Only use brown cardboard without any text because text = ink and you don't want that in the garden. Best is to find large pieces of cardboard. I was lucky to find quite a few of those.

- Absolutely do not use any cardboard with glue. If you look at a cardboard box, you will see that it is glued in one corner. I have cut this out of all the boxes that I used. Cardboard is often double layered with glue in-between but apparently that kind of glue is something natural and thus harmless.

- Remove all tape because that too is glue. I even went as far as to cut out the pieces of cardboard that had tape. I don't think it's necessary. Removing the tape should be sufficient.

Putting the cardboard down.

This is easy as pie. I used a simple steak knife to cut the cardboard. I found that a serrated knife works the best. I measured the distance between my rows and cut the cardboard accordingly. I made sure that the pieces overlap. It's very strongly suggested to weed before putting the cardboard down.

Also, I didn't read about this but found out the hard way: put the cardboard down when the ground is dry. I noticed that in some places where the ground was wet, the water stays on the cardboard after it rains. This is not happening in places where I put the cardboard on dry soil.

The use of mulch.

I read on several sites that you should put mulch on top of the cardboard in order to keep it in place. I don't want to bother with mulch and so far, all my cardboard has stayed in place on its own. I've also read that some people use stones to keep the cardboard down. Since I use very long pieces of cardboard, I don't think it's necessary to do so. I'd say use your judgement. I've had no problems at all with the wind blowing the cardboard around, it has not happened so far.

In some places where I used smaller pieces of cardboard, I covered it with hay and grass clippings.

To decompose or not.

My neighbor tried using cardboard as weed barrier once, but he had to drag it all out of his garden after a few months because it was not decomposing. He did put it down in autumn and dragged it out in springtime. I put mine down in springtime and hope it will be decomposed by next spring.

I noticed that in the spots where I put hay and grass clippings on top of the cardboard, it decomposes faster.  Overall, I think that using cardboard as weed barrier is worth it. I'll update this post next spring as I should know by then whether the cardboard fully decomposed or not.

A major advantage of using cardboard as weed barrier is that the cardboard will feed the soil after decomposing. Only a little though. It isn't horse manure :)