Beginner Gardening: Black bottoms on tomatoes and mushy yellow cucumbers??, 1 by Denine

Denine wrote:
Hello all,

I moved into this house two summers ago, and I'm having trouble with my vegetable bed. This year's tomatoes either had black bottoms, or split tops. What causes this? Also, my cucumbers refused to turn green and ripen. Each cuc would start out okay and then turn yellow and get all wrinkly and sickly looking. I tried leaving them out for the squirrels and even they wouldn't take them! ;)

Last year I had a mold problem with my zucchinis, so I am thinking that this garden bed is now shot...any suggestions?