Once round-up hits the dirt it becomes inert, so there isn't much of a wait.
But to really kill the grass I would follow up your initial spraying with round two. Then dig up the dead grass (after a few days)and amend the soil. Pull out any grass roots you find while you are turning over the soil and you may have gotten rid of the grass.

You don't really need to use round-up at all for that purpose. You can dig holes and amend the holes to plant what you plan to plant, connect the edging from the two beds, cover the whole thing (around the plants that you just planted) with a few thicknesses of newspaper, some manure, and plenty of mulch. The newspaper will decompose and condition the soil and it will attract worms, and the newspaper, the worm castings, the manure and the dead grass will all improve the soil.

That's what I did anyway, and it works. My garden is still a work in progress but really is a cottage garden; I've got at least 15-20 rosebushes, and hollyhocks, dahlias, bee balm, three kinds of irises and dianthus, euphorbia, brugmansia, blueberry bushes, chamaecyparis and viburnum and american hollies and physostegia and scabiosa and daffodils in the spring -- well, a lot of stuff, and it's all in a small front yard of a small city house. It's not as neat as I would like it because I am short on time but it's mine!

Even though round-up is touted as being safe, I only use it for poison ivy, basically; I feel that you never know and I don't want to kill the micro-organisms in the soil.

Sorry, plays in the dirt; just had to get all ecological on ya!

Rose

Rose, I have heard about preparing beds that way. I'm not sure it would work for me, reason being we have free roaming chickens and they don't let anything sit still on the ground in one spot very long. It would probably have to be held down with rocks or something. Which I guess I could still do!

How much news paper are we talking about? And how long does this process usually take?
Thanks

With lasagna gardening can you plant right away? You don't have to wait for the decomposition process to start, do you?
Thanks,
Pam

If it's not a huge area and doesn't have Bermuda grass (Bermuda in my opinion must be hit with herbicide at least twice), I like to slice under the sod, flip it over and cover with paper, cardboard, straw etc. Then plant right away if you want. Should be easy now with all the rain.

There is a more proper way to lasagna compost as I understand it, which includes making it a foot high, and leaving it to decompose for a season. This I'm sure is awesome but I've never done that.

I've simply cut the grass low, covered the appropriate section with about 3 to 6 thicknesses of newspaper. Wet it down, and then make sure you cover it well (the newspaper is not pretty if not covered with mulch). Then I dig holes through this. Since it's pretty much unamended clay I make a good sized hole and will put manure, mushroom compost, whatever, and mix with the clay--this helps the plant. I don't put too many amendments for shrubs because I've read that creates a bowl effect and is not a great idea.

Improving this Ga. soil is an ongoing effort and so every year I add some of my homemade (somewhat chunky!) compost or bought manure all over and cover with mulch (county and/or storebought). This all has succeeded in improving the flower beds quite a bit in just about 2.5 years but it's not by any means like "Victory Gardens" dirt yet, where you could stick your hand in up to your elbow! But it supports the plants pretty well and clay has a lot of nutrients in it, we don't want to supplant it, simply amend it.

Hope this helps.

Thanks,
Rose