|My tomatoes are in a box with the best soil for tomatoes, raised 16" from ground level, with an auto soaker watering every three days for 20 minutes. The leaves from the bottom are turning yellow, then brown, then dying. Bottoms of some tomatoes have round black spots covering the bottom. Why?
Plants are staked, grew to really lovely full size with many blossoms, then started to change.
|Your tomato plants sound as though they're under stress, and the fruits have the symptoms of Blossom-End Rot. The disease usually appears first as a water soaked spot near the blossom end. The spot enlarges and turns dark brown and leathery until it covers half the tomato. This problem is due to a calcium deficiency, often brought on by uneven watering, or excess watering. Since you water regularly, you may want to change the timing, watering only when the soil needs it and applying enough water at one time to thoroughly wet the root mass. The problem may have started with damaged feeder roots when you first transplanted your tomatoes into the garden. Finally, calcium can be unavailable to plants when excessive nitrogen is present. Remove the affected fruits, and mulch the soil to retard evaporation and help keep the soil evenly moist. Hold off on fertilizer for now. Fruit that develops after you've made some changes in the plant's care should be just fine.|