Throw your banana peels under your roses to produce bigger roses and more blooms. Just move away a little of the soil or compost, lay them down, then cover it up. The roses love the potassium. Also my roses have never had black spot.
Source: Farmers Almanac
By laidback arcing from Charleston, SC
This page contains the following solutions.
Give your rose bushes your used tea bags and banana peels. They will love you for it. Also hydrangeas will love your water from when you boil potatoes.
ThriftyFun is one of the longest running frugal living communities on the Internet. These are archives of older discussions.
For beautiful roses, I emulsify old bananas and peels in my blender with water. I pour this on the base of the rose bush. You will not believe how well this works.
I save my banana peel after eating the banana and gently dig out an opening around my roses and place the banana peel, spread out with the inside of the peel facing the ground and cover.
When transplanting rose bushes, chop banana peels (I use a blender) and place around the roots of the roses before covering the roots with soil, then water.
I have roses growing on my back fence. Year before last my flowers were nice but small. Last year I remembered my grandmother adding banana peels in the dirt around her flowers.