Building a raised garden. Do I need to kill the grass before I infill?

[Seth1968]

Hello.

It will 6" above ground, but won't be in use until next year. I figured the 6" of infill dirt would kill the grass due to lack of sunlight.

Is that right, or should I spray it with a non selective herbicide before I infill?

[nzwasp]

I built two once and I thought this but i had all sorts of weeds growing up into it.

You could put a couple of layers of landscapers fabric down or maybe you could put cardboard down under it.

[wtf im nameless]

I've heard newspaper works, but I just removed all the grass under mine.

[ExtraSlow]

Newspaper is a good choice. You don't want to be spraying chemicals down there (if its'a vegetable garden) and digging out the grass is a lot of work.
Landscaping fabric is also an option, but not worth buying it just for this. Newspaper will work fine, and it'll biodegrade within one year.

[Tik-Tok]

Landscaping fabric sucks balls. I mean it probably works to some extent, but won't stop everything. Every place I've used it in my yard, I've doubled the fabric (even quadrupled in one spot), and I still have weeds growing through.

[Seth1968]

Originally posted by Tik-Tok
Landscaping fabric sucks balls. I mean it probably works to some extent, but won't stop everything. Every place I've used it in my yard, I've doubled the fabric (even quadrupled in one spot), and I still have weeds growing through.

I gave up on landscape fabric for exactly that reason. I used tarp a few years ago for my last landscaping project, and nothing has gotten through it. Yes, I poked drain holes through it.

If I do spray it, then wouldn't the herbicide become inert by next year? Heck, I'm thinking it would be inert in a matter of days.

Without sunlight, how can vegetation grow through 6" of dirt?

[Tik-Tok]

Originally posted by Seth1968


If I do spray it, then wouldn't the herbicide become inert by next year? Heck, I'm thinking it would be inert in a matter of days.

Without sunlight, how can vegetation grow through 6" of dirt?

It still finds a way through, even with no sun. Fortunately the roots are pretty weak, and they're easily pulled out. I would think it will be inert by next year. I literally "salted the earth" in my alleyway last year to get rid of dandelions, and it would great all summer, however they're all back this year.

[Seth1968]

Originally posted by Tik-Tok



It still finds a way through, even with no sun. Fortunately the roots are pretty weak, and they're easily pulled out. I would think it will be inert by next year. I literally "salted the earth" in my alleyway last year to get rid of dandelions, and it would great all summer, however they're all back this year.

Looks like you're right on that Tik-Tok:

Photosynthesis takes place primarily in plant leaves, and little to none occurs in stems, etc.

Well, it's only $20.00 to spray it, so I guess that's what I'll do.

[pheoxs]

Originally posted by Seth1968


Without sunlight, how can vegetation grow through 6" of dirt?

Same way you can throw seeds in the ground, water them and they sprout without sunlight initially

[blitz]

Will anything you plant need to be deeper than 6" (i.e. Carrots, potatoes etc)? If so, you probably want to pull it up instead of just covering it. Even if it's dead, it probably won't be fully decomposed next spring and might act as a barrier.

[Seth1968]

^ That's a good point, but no, nothing that deep.

Well unless anyone else has something to add, I'll just spray it with the non selective herbicide.

Thanks for all the replies.

[suntan]

Rip it out and put it back on upside down. Then put soil on top.