I just sprinkle epsom salt around the plant. You are fine doing it now!
Andrew

If you're in San Francisco, unless you garden in sand near GG Park, you don't need to add epsom salts to the soil. Our NorCal coastal mountains have a lot of decomposing serpentine, which over-supplies magnesium to the soil. You don't need to add even more magnesium with epsom salts.

I garden in Mill Valley. A soils test confirmed that there is too much magnesium in the soil relative to calcium. I'm not suggesting there's an idea ratio, but in these soils, there is much, much more magnesium than calcium, and far more than is necessary for plant health.

Here's a good link that discusses the issue. Essence: add gypsum for calcium; if your soils are acid (not as likely in San Francisco as in the more northern counties), add oyster shell lime.

Here is a link that might be useful: High magnesium soils

Epsom salts(Magnesium sulfate)is not a magic bullet and should only be used if a soil test indicates it's needed.
As stated, magnesium is in sufficent amounts in most areas of the country.
At one time, based on the advice of many successful rose exhibitors, I advocated the yearly use of Epsom salts in small amounts and it was an ingredient in my fertilizer mix. I have since ceased it's use in my garden.

My thoughts on Epsom salts are the same as Karls, so, there is nothing more I can add.

What if one has completely fabricated soil mix for their roses. Such as in raised beds where there is little to no native soil, but a mixture of manure, peat moss, etc. I know of a few folks who use primarily a potting mix such as pro mix and just add some organic material - either garden compost or mushroom compost. In this case would you advise the use of epsom salts or I suppose one should still have a soil sample taken.

I do live in sandy soil, I am near ocean beach and the house is build on a sand dune. There is nothing, but sand in my garden and the things I added.

What is the best time to add the Epsom salt? I believe I got good results when I added it a few years ago. For example I found out the time to add aluminum sulfate to the hydrangea is when it's budding. So do I add the Epsom salts when the roses are budding to improve flower color intensity?

Karl and berndoodle are right.
Don't add it AT ALL, unless you have done a soils test, and found that you need it.

Jeri

Hey, have at it. This is a good time to fertilize roses and to add mulch if it's gotten thin.

I doubt that Epsom salt will do any good for your roses. As matter of fact seldom they need phosphorus added because phosphorus will kill the beneficial nemathodes on the rose roots they need. Make a search for mythe/urban legends at Washington University wen site for this subject,

If your soil is indeed alkaline, you do need to add garden sulfur, twice a year that helps - a lot. Keep the epsom salt for your tomatoes to prevent early blight; though even for early blight I found that calcium nitrate works better although it is slightly more expensive.

I found this website by the Epsom Salts Council. They said use it every two weeks, which I think would be too much, but it does not have any phosphorus. It does not change the soil ph. Maybe the person who posted that is thinking of bone meal that has phosphorus? I never heard anything about phosphorus killing off beneficial nematodes. I don't have any nematodes maybe you mean the microherd? I did add a little bit yesterday, but I would only add it like once or twice a year. I don't believe it over doing things. I do a lot of composting.

Here is a link that might be useful: Epsom Salts Council

Sorry about the nematodes, I meant beneficial fungi - I better stop writing when I don't sleep for days.

Thanks! I'll use the epsom salts in the bath tub!!

We have lived on our rural property for more than 15 years and in all that time the deer have stayed away from our roses. Not so this year tho! Bambi and her yearling have nibbled all the new shoots over a period of two days and the roses look very odd to say the least. I am putting up a plastic mesh deer fence across the back of the propery ( bush area) and down one side where I'm sure the deer are coming from, hoping to eliminate the problem. However, I'm not too sure whether I should just leave the roses and hope they grow again, or wonder if I should be pruning them lower since it was only on the upper part of the canes where there was growth.

The deer thing is a problem if those roses are graphed on other roots, and all the new rose is removed to the roots, they won't grow the rose you want, it will only be the root stock. I had a rose that put out a sucker and I thought it was a cane, so I left it and it never bloomed, but it was bigger then the entire plant, before I noticed it was coming from too low on the base and therefore was part of the graphed part. But, maybe they did not go down that far, or maybe those are not graphed roses. If you post photos and give the name of the types, I am sure some rose people here can figure it out.

I don't think episom salts are bad, it's not like adding sodium. It may be called salt, but it's not the same thing as sodium. But, that was not the question. I had already decided to use them and I had used them before. So, I don't know why I am getting some many replies re that epsom salts are bad. It's not like they are making a killing selling something expensive like a plant food as suggested above. They are not costly, so I don't see why they would bother to have a conspiracy to sell bad things that ruin plants. Most harmful things they sell to you make them a big profit like fat burners or other diet pills. I picked up a supply for two dollars that will last me about 10 years or longer, but usually they kind of harden up before one can use them all.

Bub, no one said Epsom Salts are bad, as such.
Everyone's telling you that you should not use them unless there is a deficiency indicating a need for them.

That's a different thing.

But you go right ahead. :-)

Jeri

I agree with Jeri. If you insist on using Epsom salts without determining they are needed in your soil, go right ahead.
A tablespoon at the dripline of each bush or dissolved and applied with a sprinkling can will suffice. With Epsom salts, a little goes a long way.
I hope they give you the results you want.