Have you tried rhubarb juice on your roses?
Rhubarb is a vegetable often used to make desserts. But its leaves are used by organic gardeners to protect roses from greenfly and black spot.
You should boil rhubarb leaves in water and make a spray from this. Spray it on your roses to get rid of greenfly and black spots, says Louise Riotte in her book Companion Planting for Successful Gardening.
She says that garlic and onions are very good guardians of the rose. In Bulgaria which produces attar of roses both garlic and onions are interplanted with roses and they amazingly cause the roses to produce a stronger perfume in larger amounts!
Roses are also helped by planting parsley, mignonette and lupines around them to increase soil nitrogen and attract earthworms, she says. Rue planted near roses or raspberries will deter the Japanese beetle.
Rue also helps to get rid of fleas! It can be used on dog pillows or beds, says Riotte but cats don’t like it so spare them!
But if you don’t like them scratching at your furniture, you can spread rue over it and the cats will keep away.
A tea made of horsetail is gentle but very effective for fighting mildew on roses.
Pics and text: daksha