Ask-a-Dave's-Gardener: Swedish Ivy veins on leaves turning red, 1 by ferrad1

ferrad1 wrote:
I have a large Swedish Ivy (I think it\'s called that - we call it a money plant in South Africa). It could also be called Plectranthus. Anyway I have taken a number of branches off over the last few months as it is getting old. I put them in water until they grow roots and replant. They start off beautifully, but over time the oldest one has started getting red veins. See the photos below. I planted the newer two about a month ago. The older one was planted about 4 months ago. Why are the veins going red and how do I get them back to pure green?