Q: I have plum trees. Information from the University of Georgia says to fertilize them with calcium nitrate. What is this and where do I get some?

A: Calcium nitrate is a specialty fertilizer for fruit trees. It does not acidify soil like most fertilizers do. I rarely see it at garden centers but have seen it for sale on the Internet. In my opinion, you can in March apply one cup of 10-10-10 fertilizer per year of tree age to a maximum of 10 cups for mature trees. Each August apply one cup of 10-10-10 per year of tree age to a maximum of four cups.