I recommend adding compost either home made or from a bag you can purchase at the garden center. Add the compost on top of the soil in the fall after you pull up the harvested tomato plants. You do not need to work the compost into the soil. Just apply a 3 to 5 inch compost layer and the worms will mix it for you. Then in the spring you can replant your raised beds without any tilling or digging. You might also consider adding well rotted manure, chicken manure or rotted leaves on top of the soil this fall. The manure will continue to rot and improve the soil over the winter. Keep growing, Marianne Binetti