Have you checked your pH? Many chlorosis problems are due to a pH imbalance causing some nutrients to be insoluble & therefore not available to the plants. You say you are in a very dry climate which usually results in alkaline soil (pH over 7)& this pH level causes iron, manganese, zinc, copper & cobalt to all be insoluble.

I would not use Ironite. It is a mined waste product which contains significant amounts of lead and arsenic and other heavy metals. The company argues that the arsenic and lead are in very insoluble forms but they ignore such things as: 1) The lead and arsenic can become soluble if you make the soil acidic and 2) Who would really want them in one's soil in any case?

Iron deficiency in roses often appears in Spring when the plants are growing rapidly. If your soil is alkaline, lowering the soil pH may help, but this is a slow process and usually has to be repeated on a regular basis. It's just as easy to feed soluble forms of iron on a regular basis, just as you would any other fertilizer nutrient. Some things that have worked for me include a sort of natural chelate made from mixing a cup of ferrous sulfate with a 5 gallon pail of equal parts peat moss and garden soil. I spread a few cups of this mix in a ring around the plant.

Here is a link that might be useful: Ironite Law Suit

Below is a link to another product that you can use for iron plus some of the other micronutrients. I used it when I lived in an area with high pH due to limestone bedrock below my garden & it worked well on those roses that were sensitive to iron chlorosis. I applied it as a soil drench , not as a spray on my roses & a word of caution, it stains just about everything it comes into contact with.

Here is a link that might be useful: liq. chelated iron

I use the Rapi-test meter to check pH. I apply sulfur to lower the pH around plants that show iron, Mg, or Mn deficiency (1/2 cup/sq. yard), but it takes up to two years to work. Meanwhile use some iron product other than Ironite. Mike's recipe works, but be sure to moisten the peat thoroughly.

Thanks for the info about the ironite. Sure don't need to be adding any heavy metals to the soil. My soil is alkaline - all the soil in this area is. It does seem to be worse early in the season. I have some sulphur so will apply according to package directions and also use a different source for the iron. Will the yellow leaves turn back to green or will they eventually die and be replaced by new leaves? I love that there are so many knowledgeable people willing to help on this forum. Things I have learned from reading this forum have enabled me to rejuvenate the 4 roses in question and enabled me (in a different way *G*) to add an additional 10 roses to my yard.

Chlorotic eaves can green up, but it is slow. New leaves should come in green if what you are doing is working.

For the past two years my Frederic Mistral had turned into a chlorotic monster in our alkaline soil from early spring until late June. I used various products with limited success until this year when I tried a product that totally eliminated the chlorosis from the very beginning of spring. It is Hi Yield Iron Plus Soil Acidifier. It's like FM is a whole new rose. This product contains nitrogen, sulfur, and iron. I will definitely use it again if necessary. Diane

Epsom salts (magnesium) usuaqlly helps to green plants up

I created a problem for myself a couple of years ago & used a liquid chelated iron product to rectify it.

Like most other problems, the 'fix' takes longer to take effect than it did for the problem to show up & worsen. In other words, decline was rapid but recovery was much slower. Still, I could see results in about 2 weeks.

I've only had to use that product once, and now I take better care of soil pH so that the problem doesn't resurface. The soil in parts of our yard is such thick clay that I could probably start a pottery guild.

Thanks again for all of the great info. I saw some High Yield Iron plus Acidifier at a local store and some chelated iron products - will choose one and apply. The soil where the roses are planted was brick-like clay when I moved here but 7 years of compost and mulch have softened it up somewhat. My neighbors said that those roses never recieved any care or supplemental water for years before I moved in - I'm amazed they lived because we have so little precip in this area. It's been gratifying to be able to revive them - they are blooming like maniacs; even the one with the worst chorosis.