Q: I have already placed wheat straw around my tomatoes but I failed to add any lime to prevent blossom end rot. What can I do at this point?

A: Blossom end rot is caused by a lack of calcium in immature fruit. Go to a big box hardware store and look for broken pieces of gypsum wallboard (Sheetrock, etc) on the floor. Take a few home, pulverize pieces with a hammer, and sprinkle 2 TBS of the white powder around each plant. Gypsum contains calcium sulfate, which supplies vital calcium to tomatoes. Do not use Epsom salts on your plants, since magnesium competes with calcium for uptake by the plants.