Round-up does not last from season to season. It is a contact killer, meaning it has to come into contact with the surface of the plant, once it is in the dirt it becomes inert. Putting down weed blocker is still a good idea to help you with weed control.

The plants should not be affected by Roundup used in the past with or without the "blocks" you mention. Roundup breaks down in soil within a few days. Your additions may help make the soil better for growing by adding some nutrients and organic matter, retaining moisture, and controlling weed growth.

FYI, Roundup is sprayed on leaves and then moves through the plant and kills them. Uptake through the roots is not an effective way to kill plants/weed with Roundup.

If the previous owner used other products with a pre-emergent herbicide you may need to wait a few months to get good germination of directly seeded veggies as those chemicals take longer to break down. Transplants should grow okay, though.

Will confirm that RoundUp (glyphosate) breaks down in the soil rather rapidly. It degrades into harmless chemical compounds by the activity of the soil biology and by exposure to sunlight and water. And I wouldn't worry about any pre-emergents in a raised bed situation either. They only affect seed germination or root formation on seedlings, neither of which will be a concern with thick layer of soil over the top.

Do NOT use landscape/weed fabric under the beds. It impedes proper water movement and won't allow plant roots to penetrate into the underlying indigenous soil. If you need to smother grass or weeds, use layers of thoroughly moistened newspaper or cardboard to cover the area before adding your planting soil. It is completely biodegradable and will decompose after doing its job.

btw, you want real soil in your raised beds, not just compost. Just fill with soil from the garden or purchased top soil. You can certainly amend with some compost to improve fertility and lighten the soil/help to retain moisture but it should not be the only material in a raised bed.

"Do NOT use landscape/seed fabric under the beds. It impedes proper water movement and won't allow plant roots to penetrate into the underlying indigenous soil."

Amen to that.

Dave