Hello everyone. I planted several Purple Pavement roses about a month ago and one is turning increasingly yellow, that is, yellow leaves with green veins. Drainage appears good, although I have not dug up the plant to check for problems deeper down. So, I am thinking that it may be a ph problem. I live in Chisago County, MN, on the St. Croix River, zone 4. The soil is somewhat sandy but it was well amended with compost and a rose soil mix recommended by a local nursery. According to the city the water is alkaline at 7.2 and my soil runs between 7 to 7.2. Assuming it is the ph level, is it safe to use sulfur or aluminum sulfate on such a newly planted rose? The plant was a five gallon and it has grown steadily. I have tried one dose of liquid iron with no improvement - at least not yet. I would appreciate any suggestions. Thank you.