Some roses usually have a row of "guard petels" on the outside which are smaller, coarser, and colored differently. Often these have green or white veining. These can be pulled off if you don't like them. If you could post pictures along with the variety name, people might have better ideas.

I'm skeptical about soil depletion, especially since you add manure and fertilizer. It's possible that too much of something, such as calcium or potassium, caused the magnesium deficiency. Lowering the pH to around 6.5 would increase the availability of several nutrients. You should check the pH, but if you don't, 1/2 cup of sulfur per square yard should be OK. It takes a year to work.

I have a huge shrub rose that has grown in the same mediocre soil for 25 years without fertilizer or even mulch added, and it's currently covered with bloom. (OK, maybe I throw a handful of 10-10-10 at it every few years.)

Part of the problem could be over "mothering" the plants. I started planting roses before I knew a damn thing about gardening - sometimes even in mostly shade - and they usually performed beautifully. Now that I think I know a lot about gardening I find all sorts of problems and create a few too!

However, the native soil is weird around my current house - at about 1' down it smells terrible (rotten egg smell), probably due to a lack of any oxygen. I removed one well performing rose from this location a few years ago and I remember that the roots extended well into the native soil even though it was like very wet pottery clay. However, I suspect a rose in this environment won't last.

I also forgot to mention that the newer leaves look a bit odd, like they are partially folded with some hook which is usually a mineral defficiency. I also have a little powdery mildew this year due to the very high number of overcast/rainy days this year. Since I never get much mildew, I don't really know what the effects are, if any.

I'll definitely buy a soil test kit and check the PH although I can only sample down to about 1' or so w/o really tearing things up.

Unfortunately I lost the tag for the rose pictured below but in past years this blossom was like porcelain. As you can see the outer petals are very distorted and the rest are very poorly pigmented and almost immediately wilt upon picking. The pigmentation actually looks much worse in person.

{{gwi:273313}}

Guard petals often take the brunt of weather damage.

Remove them, and the bloom will open normally.

Jeri

I would consider getting the Rapi-Test pH meter rather than a soil test kit, although it might be useful to see if the soil has excessive phosphate and potassium from over-fertilizing. Clay soils retain any excess that the plant doesn't use; nutrients and non-nutrient salts build up. Take the soil sample about 3" deep; that's where the feeder roots are.

Even though you are in California and don't have access to cheap ag extension testing, I think it would be worthwhile to spring for a complete professional soil test. It may be your fertilizing habits are part of the problem. If you think there are nutrient imbalances, find out what they are.

If the soil smells sewagey one foot down, you need to improve the drainage. Usually the best way to do that is to raise the soil level to provide at least a few inches more of drainable soil.

Thats the test kit I use - I get tired of buying the whole kit - can you buy the capsules in bulk online?