The leaf with yellow veins is just dying. The cause could be water logging if it is widespread on the lower leaves. Otherwise, it's just a senile leaf that the plant is ditching.

Pale leaves with green veins on the newer leaves is iron deficiency, a mild case that might be caused by too much water. Use a fertilizer with chelated iron.

Leaves with yellow margins and green centers show magnesium deficiency. Normally this affects the oldest leaves first. Apply 1/4 cup epsom salts.

Check the pH. Florida soils with marl, shell, or coral may be alkaline, and that can contribute to mineral deficiencies. Sandy soils don't hold nutrients well and call for organic or timed release ferts with trace elements.

Thanks so much, Michael! I will try time release fertilizer. I have added Epsom salts but it must be washing away? It didn't seem to help. Any preference on time release fertilizers? I know of osmocote but is the one for roses, especially? I have Mills Mix that doesn't seem to make a difference either. I have wondered about the pH b/c nothing is working (at least that I can tell. I have reclaimed water, but even if it had too much salt with this rain it shouldn't matter?

Awesome! Thanks!!

There seem to be a general nutrient deficiency going on here. On top of the obvious magnesium deficiency there may be others involved including most probably nitrogen and there maybe some potassium deficiency involved. I cannot discern any obvious iron deficiency in these pics (this shows first on the newer leaves). I would refrain from using too much phosphorous and apply nitrogen, magnesium and potassium. All this is just speculative of course, I would suggest to have your soil tested to know where you're coming from. Quick relief from magnesium deficiency can be provided by foliarly spraying. Magnesium uptake from the soil can be slow.

Thanks Nik. I agree it seems to be a general deficiency of nutrients, but obvious magnesium deficiency. It started with the rain. What does the phosphorous do in impeding uptake of the other elements? Yes I should have it tested. I bought a kit, but the sand is so silty that it wouldn't settle out of solution in time for me to read it. Or maybe there was nothing to read. ( I could read the color change in pH, 7, but no obvious color change in N,P,K.) If I do use foliage spray and it corrects the deficiency, do the leaves green up again or do they stay the same, and the correction just helps the newer foliage from showing stress from lack of nutrients? So far nothing is working, but maybe it takes time, as you said. .. I am going to amend the soil with horse manure ( I have put that off due to rains, and imagining horrified neighbors watch manure washing down the back alley while waiting to be unloaded- so need delivery and I have to unload all in one day...)

In general P is not deficient in most garden soils (again that's talking without knowing your particular situation). In addition roses do not seem to be heavy P users (cereals are). Most gardens could easily flourish without any P addition. P also does not easily leach with rain. Excessive P can affect greatly the availability of other nutrients (mainly iron but others also). All this is just theoretical and greatly depend on your pH also. But this is the general idea.

Applying a foliar spray of N and Mg wil probably quickly fix some of your issues (in the space of a few days). If your soil is Mg deficient then you should apply Mg in the soil also. I'm pretty sure you will need to add N too (easily leaches out and is the single most important nutrient in a garden environment and the one most commonly in deficit). But you won't know if the soil is deficient in Mg until you test it. What I'm trying to say is that a plant can be deficient of a nutrient while the nutrient exists in the soil and there are other reasons that can bind it in the soil so the roots cannot uptake it or the roots cannot uptake it because of wrong soil conditions (wrong pH). Professional produce growers get both the soil and the leaves tested to know exactly what's going on.

The leaves green up again if they are not beginning to senate.

Nik and Michael, you have both been very helpful. University of FL can test soil. I should use them through my local agricultural office. It is very interesting to learn how the various nutrients affect growth, etc. I thought P was what roses need to bloom. I must have had plenty in spring, winter and fall, our dry season, but not so much now. Trying to figure this out is complicated. I have always thought the heat made the roses stop blooming, but maybe it's the lack of nutrients in summer due to excess rain, maybe both?

Nik is correct. Phosphorus forms insoluble compounds with iron, copper, zinc etc. UF has reported soil problems caused by overuse of P on roses (caused in turn by the widespread myth of "P for blooms"),

The home test kits are nearly useless. Contact your county agent.

I recommend adding clay to sandy soil, 10-15 per cent plain cat litter by volume. And of course manure. These will help the soil retain nutrients when itr is raining an inch per day.

Nik and Michael, I appreciate all of the constructive help!! It is so refreshing to find such knowlegeable people as this forum has! I am a newcomer here, but feel right at home! Thanks!

If your pH test turns out to be wrong and your soil is acid, I would suspect that what is being recognized as magnesium deficiency is actually boron toxicity -- far more common in central Florida roses than is Mg deficiency. If that's the case, raising the soil pH would correct it immediately. But if your soil pH is actually 7, it is likely Mg deficiency. That causes one to wonder why epsom salts has not helped, though. If your soil pH were much above 7, that could impede uptake of Mg from the soil. The Duchesse de Brabant leaves do show classic iron deficiency (light green newer leaves with deeper green veins), suggesting your pH may be higher than 7. So I'd agree that an accurate pH test is in order. Also be aware that in a rose bed with highly amended soil and a history of varied fertilizer use among the plants, you can have wildly differing pH values between individual roses in the bed. We commonly find pH in the 4s under older, long-established bushes in highly organic soils, and up to 7.2 in adjacent, newer-planted plants, in our garden beds. And in those older plants in the highly acidic soils, the first symptom we see that alerts us to the problem is always the boron toxicity that looks like magnesium deficiency.

Thanks to Dr. Manners.

Thank you Dr. Manners, I have a newly planted garden behind a 100 year old house. Our house and garden was suffering from very extreme neglect. We removed about 35 trees that had grown together from a 60' x 140' lot, surrounding the house. While restoring the house, during site work the garden was stripped of topsoil... I am guessing that we are at least 7 pH maybe higher, due to the concrete footers around the garage and wall which are new. . But that is a good reason to test. There is no telling what we have?