When can I plant after applying weed and grass killer

[jim99rock]

Please help.
I for five years now tried to naturally kill off the grass in my garden section. I started by taking 4 inches of grass and dirt. Then covering the ground in the winter to choke them out and this year I will be placing plastic and putting new top soil down, but would like to kill the strong thistle that has started to grow.

Thanks for you thoughts

[pruninggal]

I wouldn't use plastic or landscape fabric if I were you. Plastic is just nasty and won't hold back weeds whose seeds happen to land on top of the soil resting on the plastic. Plus, in 4 or 5 years the weeds may be just as bad and you'll be stuck with all the plastic or fabric in your soil. Cardboard or thick newspaper will do the same trick and will break down in the soil. You can plant through it or leave enough room for planting. Just make sure to leave enough room for water to get to the roots. IMO, this is your best bet...

Good luck,
Katy