Question
After pruning back in So. Calif. I was told about adding epson salts to help my roses. How is this applied and what does it do? You have a great site! Thanks.

Answer
Ah yes.The Epsom Salts debate. You do have to be careful when these so called miracles take off especially on the plant forums. It is best to wait until the agricultural universities or government agriculturals departments have tested them. This all started with Epson Salts really helping making evergreens go a nice rich green colour and certain vegetables producing better and larger yields.
But in regards to roses. Roses are programmed to grow at their own particular rate and type of growth. Such as, some grow by making many nice basal canes while others only make a few basals and then enlarge but making lateral canes. No matter what you do or put on them nothing will change this. However it has been proven that a small amount of Epsom Salts will make the leaves healthier and the flowers better coloured. All this will happen quickly if your soil is lacking in magnesium. If you haven't had your soil tested then to be on the safe side I would use the Epson Salts as a foliar spray. Mix 2 tablespoons with a gallon of water and spray every month. Now if your soil is rich in magnesium it won't effect the roots. Epson Salts placed around the base of a rose can kill the bacterial which break down the nutrients so the rose roots can take them up easier. Too much magnesium will tend to make the soil go more acid which will cause problems for the rose. Most of the hype about these salts. as I said, has come from vegetables and evergreens and then they have simply transferred it to roses. Roses really do prefer to constantly munch on food and that is why they respond so well to mulches. Also if a rose isn't doing well it probably has nothing to do with the gardener but the rose itself is a dud. Hope this helps.