A couple follow-up questions.
1. I will stop fertilizing when it cools off. Do you think all the rain we get in the fall/winter here will leach some/enough of the Cl2 and PO4 out of the soil? (ugh ironic... TS Lee is on its way. We are suppose to get 6-8". I think you are suppose to get more in the mountains.)

2. If I added some lime, could it possibly bind the PO4 to reduce toxicity.

3. I'd rather switch to a slow release fertilizer, but I don't have as good a feel for how much and when it is running out. I only used this one because it was the only quick release I could find with micronutrients. Any recommendations?

4. Thanks for the tips. They don't show any signs of problems now, but for next summer, I'll slow it down and keep my eye out for what you've mentioned.

I'm sure you don't have a problem at this point--it could take a decade of over-fertilizing to create a soil problem. Phosphate isn't toxic; the long-term condition that sometimes arises is that PO4 ties up metallic trace elements in insoluble forms, causing deficiency in the plants. I've never actually observed this, but UF extension says it occurs in some rose gardens. There is no way to get rid of excess PO4.

However, heavy rains will remove any nitrate nitrogen that is in the soil. Unused ammonium in the soil will evolve to nitrate and leach out. That's why fast-release fertilizers need to be reapplied at intervals.

Short-term foliage burn is most often caused by a temporary excess of ammonium nitrogen.

The fertilizer you are using is fine, I'm sure. A 2-1-2 or 3-1-2 ratio is slightly preferable to 1-1-1, but I've often used 10-10-10. Many people like Espoma Rose Tone or Plant Tone, which are organic. Roses can use around 3 cups a year. These are 3-4% nitrogen, mostly slow release.

Fertilizer labels often suggest a maximum rather than an optimal dose

You shouldn't need to add micronutrients with every fertilizing if you're growing in soil. Those complete, micronutrient formulations were originally intended for commercial nursery operations growing plants in artificial media (ground up bark, no soil) and watering multiple times per day.

The only nutrient you really need to add so often is nitrogen. It is used in large amounts, and is very mobile so quickly lost. P and K are not lost so easily so don't need to be replenished so often. In fact with the P it's a matter of adding very small amounts as there's usually plenty in the soil, just not in a form the plants can use. Especially if you have clay, or lots of iron or calcium, P gets tied up with those.

Your regime sounds too much - too much fertilizer, too much work, too much money - but your roses are not showing damage. It is entirely possible to get over fertilizing damage, but rain will wash some out, depending on what kind of soil you have! Clay does not wash out readily, whereas sand does.

Topdressing with compost and/or manure once or twice a year should take care of most micronutrient needs. And my own preference is to fertilize after every bloom cycle, not once a month. Months are human constructs. The rose's physiological needs go by bloom cycles, which are generally about 6 weeks long. People feel they need the structure of the calendar month to remember to fertilize, but you can easily train yourself to remember that every time you do a major deadheading, which usually means the end of a bloom cycle.

Why not take the guess work out of it and have a soil test done? Preferably one by your county ag department. When I had mine done 25 years ago I was told that my soil lacked nothing but Nitrogen. In fact the P,K were so high (as is the case with most heavy clay soil) that adding more could actually do harm. Remove all doubt as to what your roses need by having a soil test done......Maryl

I agree with Maryl - a soil test is a must. I bought a kit today at Lowe's - they are pretty accurate for $11. It's a good deal for at least 10 times of testing.

We have dark topsoil on top, but yellowish clay at the bottom. I tested the yellowish clay first: super-high in potassium (K) and phosphorus (P) as Maryl said about heavy clay soil. It's also low in Nitrogen.

The dark topsoil is slightly acidic (amended with peatmoss). I test the pH of composted horse manure, it's neutral at 7. I put baking soda in, and it turned to the 8 and 9 alkaline range as expected.

I used to dump Bayer granular fertilizer (with insecticides) on my roses. The high nitrogen only encourages more asphids and Japanese Beetles. Then I skipped doing it for a few years - zero asphids and much less Japanese beetles. Later I found that high nitrogen encourages asphids.

There's the salt issue, chemical fertilizer is highest in salt, next is manure, next is blood meal, and the least salt is the oragnics (alfalfa, grass clippings, leaves). When I used chemical fertilizer, I had to water my roses. When I don't use chemical fertilizer, I can stop watering my Knockout & Flowercarpet for good.

Salt doesn't go away with poor drainage clay. Few years ago my 3-years old daughter "shake-and-bake" my tomato garden with the 10-10-10 pellets fertilizer. The tomato plants got all burnt and yellow. We fixed the garden by scooping all the soil and dumped on a big white pine. That large white pine turned from robust green to burnt brown. It took 5 years and lots of heavy rains in Illinois to undo the damage. That large white pine is never the same, and it's the only one that I have to water out of my 26 trees.

Conclusion: If you want your roses to handle drought better, skip the chemical fertilizer, put less salt in soil, and your roses can flourish with less watering. Less watering also means less insects. Insects are attracted to water sources.