You’re probably better off adding soil. For tomatoes and peppers, anyway. You can get good garden soil at a home center. Or even pot them. Tomatoes need a 5 gallon pot. Peppers can deal with half that
just researched online. it says sandy soil is not great for roses, because the water drains too quickly. mine is a mix of soil clay and river sand, maybe that is what my caseworker was talking about.