Growing rosebushes in your yard has its rewards when the plant matures and thrives. But in the early stages, it’s key to do whatever you can do to protect the bushes from disease. One handy natural idea is to place banana peels around the perimeter of the plant. The peel is an easily compostable material that will break down and give the rosebush potassium-rich nutrients. This boosts the bush's natural immune system and lets it fend off frost, drought and other threats that can hurt it in the early stages.