Answer: Purple discoloration is most always a sign of phosphorous deficiency. In container soils, this happens when fertililer with phosphorous (the second number on a bag of plant food) isn't applied on a regular basis. In the open ground, phosphorous deficiency may occur if the soil pH is too low (acid) or too cold and wet. To remedy the first situation, apply light but regulatr aplications of a liquid fertilizer. To remedy the second, have a soil test performed to determine your pH. Young tomato plants do like soil temps of at least 60 degrees F.
Q&A Library Searching Tips