The advice against planting strawberries where tomatoes once grew is due to diseases that affect both, especially Verticillium wilt. If your tomato plants were healthy, I wouldn't worry too much about planting strawberries there. If you noticed that the tips of the branches on your tomato plants were wilting for no apparent reason, you may have cause for concern.

If the tomatoes were infected with Verticillium, a few inches of new soil over top of the old soil will not keep your strawberries from being infected too, because the strawberry roots will reach down into the old infested soil. You would need to choose varieties known to be tolerant of Verticillium if you were determined to grow strawberries in that situation.

The best advantage of a raised bed would be good drainage, which strawberries also need.

The only disadvantage to a raised bed is that they tend to dry out faster than ground level plantings and strawberries are shallow rooted. So be prepared to water.

WHat is something good to use to prevent verticillium wilt? What are the sypmtoms of it?