Beginner Gardening: Weeds and Garden beds., 1 by Serramarra

Serramarra wrote:
Hello I have a couple of questions:

I am having weeding problems. Before starting my big garden bed I completely pulled up existing flowers, tilled the soil. Laid down weed preventer, and mulch as I planted new and replanted old flowers. Grass and weeds started growing up anyway immediately, It is a big area. I am thinking of pulling up the plants I have down, in the fall to use a weed killer like round up waiting a couple of weeks then putting the flowers down again with the weed preventer, soil and mulch. Do you guys and gals think this will kill the flowers or harm the soil to the point I won't be able to plant the flowers back? is there another way I should go about this? I wanted to wait till the fall because this was a recent planting. I had already had some flowers down in my bed but because of the weeds dug them up to get all the weeds out and I don't want to pull anything back up until it is healthy again. Any advice would be appreciated...Thanks

I have in the garden now
gladioluses,
Hyacinths
toad lilies
mountain lilies
oriental lilies
angelique tulips
Hosta's
Arum Corntum(Vodoo lili