QuestionI planted two rugosa blandc double de corbert this spring. They now have brown leaves on them its no crunchy brown though. I have watered about every other day and mulched with pine needles I have also fertilized with Miracle Gro rose food. These plants get sun all day long. What is causing the brown leaves? Thanks!
AnswerI know the books tell you that Rugosas are really tough and hardy but that only applies to when they are established. Before that they can be a real pain. Most Rugosas will not tolerate chemical fertilizers and will re-act to it, especially when the roots are not settled in. They also will not take any insect spray or sprays of any kind. Right now they are in a snit but they will settle down and make nice new canes but you may have to wait until next spring. All Rugosas really need is to be planted in a hole with reasonably good soil and then have a mulch over the roots. Roses love cool roots. As you have already done everything for them I would just keep watering and simply ignore their complaining but don't fertilize them any more. The pine mulch is food enough. Next spring just use something like a bag of steer manure and that will be good for the whole season. Blanc Double de Coubert has an annoying habit of the outer petals turning brown. Alas, there is nothing you can do about it as it is in the rose genetics. Hope this helps.
