Never used weed barrier myself - just a couple of layers of cardboard. It rots eventually so the worms have access and it blocks the weeds too but it doesn't prevent or retard drainage as weed barriers can - you don't want to end up with a pond under the bed. ;)

Dave

I built a raised bed using 18" sides of plywood (reinforced with 2x4 ribs). I put weed barrier under that box because I know that morning glory would quickly invade that raised bed. I grew tomatoes and peppers in that raised bed. No issues.

I moved my garden to another location and moved the soil from that raised bed to the new beds. The spot where the raised bed had been was weed-free for the next season.

For my yard, I think no weed barrier under the bed.

Five years ago, I laid weed barriers on the first two raised beds built. Most herb grew ok but some not great. The garlic chives get an ok harvest every two month.

Two years ago, I skipped the weed barriers for two new beds. Most things grew much better given more room for the root. I moved some garlic chives from the old bed to the new ones and the harvest turned once a week. Some stubborn weeds did come back but not much.

Last year I used newspaper and cardboard boxes under the newest raised beds because the ground cover were three feet tall underneath. Weeds are even less to almost none.

I would say no weed barrier, too. I've tried a few of those barriers, and if there's one, single type of weed that can get through it, it's running grasses. Their tip shoots are designed like needles and all they have to do is get one of those tips through a tiny, tiny hole in the fabric, and they're in.

I don't have the patience to lay newspaper anymore, but if you use it, lay it down THICK and WET. I use cardboard, scrounged from appliance and furniture stores. I've used up to 6-ply cardboard with no breakdown issues.

IMPORTANT when using cardboard or newspaper with grass nearby. Lay your cardboard down so it sticks out at least a foot outside your bed edging. Set the boxes right on top of the cardboard, don't just butt the edges up to the wood. Then mulch that outer rim of exposed cardboard with bark or straw or leaves or something. Keep the area around the beds clear of grass (esp running types), or it WILL work its way into the beds. Guess how I know???

Sue

I have the same question as the original poster, but my concern is a little different. I'm concerned that the roots of the vegetables (especially tomatoes) won't be able to penetrate down deep enough if there is a weed barrier (cloth, cardboard, or otherwise) in the way. I would think newspaper could work quite well, though. I'm planning on putting in raised beds that are a foot high.

Do I need to worry that the tomato roots won't be able to penetrate the weed barrier or is there no problem with that?

Thanks,
High desert gardener

If the box is deep, such as a foot high, I question if weeds are going to grow from that far under the soil. I realize they are tenacious but if you are down to bare soil in the bottom of the box, and you add a foot of soil on top of that, I would think any weed seeds left on the surface of the original soil would have a difficult time reaching the surface even if they did manage to germinate somehow.

I used a weed barrier and grew carrots, beets, radishes and other veggies without issue.

My problems aren't with weed seeds but bermuda grass. It will run 5 foot into a raised bed with no trouble. It will weasel its way into any bed you build with any barrier you try. You just have to be very vigilant and pull out any you see and dig it back to the edge. I have tried weed fabric, cardboard, newspaper all with limited success. Cardboard has worked best for the first year but after it decomposes you are once again at risk. I have had the best luck with digging a trench around the bed and filling it with thick mulch and then putting a hard barrier on the edge. So depends on the "weed" you are trying to avoid. Bermuda is the worst "weed" I have to deal with. As much as I hate the things like roundup, I have had to resort to it with
Bermuda grass.

Hi,

DH built me 3 raised beds in 2009 and put weed barrier under each. He used the DuPont brand with the 15year rating. The stuff is cloth-like and water permeable. The raised beds are 10 inches deep. We did not grow any root crops but had no problem with roots. Not one weed grew through these raised beds -but- I think it was more the 10 inches of growing medium than the weed barrier. DH did not till the soil under he just scalped the area bare with a weed whacker. The nice thing about the weed barrier is the walkway in-between the beds is weed free -IF- you put some kind of mulch on top of the paper. This year we will add 2 more beds but they will be 20 inches tall for root crops. DH is thinking cinderblock vs. wood.

Hope this helps a bit. Hi,

DL

Growing in containers solves all these problems! I love it!

hi paloaltomark, did your carrots grow through the weed barrier?

Mark, this thread is six years old.

I understand this is an old thread, still hopeful that someone would answer my question. I have a slightly raised garden bed 8 feet away from a mature maple tree. The first season, I grew veggies, herbs, and flowers with very good results. At the beginning of the second season (last year), I noticed that the bed had been completely invaded by the tree with dense roots everywhere. I cut the roots, refreshed the soil, and planted the same things. They did not grow well, all the nutrients being sucked up by the big tree. Now, I am looking for a barrier to isolate my garden bed from the smart tree. It has to cover the bottom and one side of the bed. Any suggestions would be greatly appreciated. BTW, I cannot move the garden bed to a different location. This is the only spot that I have.

Mark, if the roots are that invasive, a weed barrier may not be enough. You might want to search in the Square Foot Gardening forums and search for "table top beds." They are actually raised off the ground with a solid bottom with drain holes. I have never built one, but they seem pretty common for those folks. Just a thought and good luck.