Pour the concrete mixture into the waiting form. Rebecca equates this part with making a gelatin dessert. After the concrete is in the form and has been roughly leveled out, you have to screed it. This involves leveling off the concrete with a 2x4. Remove any excess concrete from the top as you level it off. Rebecca decided she wanted to imprint a fern on the slab of concrete. You can also make imprints with sunflowers, daisies or any other flower than can be pushed into the concrete to leave an impression. Use the side with the most texture to make the imprint. Use a flat trowel to push the plant into the concrete and smooth the rest of the surface.
After laying the concrete, make sure you clean your tools off right away; otherwise the concrete will stick to it forever. Allow the concrete to set overnight, and you'll be able to walk on it the next day, although you have to be careful not to drag your feet, because it will scratch. You can also pull off the flower or plant forms the next day. It's a good idea to keep the slab damp for a week, either by sprinkling it or laying wet burlap over it, to make it stronger.