For the east, I have a very high pH. What I see in my garden is that certain varieties, particularly those with a lot of multiflora in their background, object to the lime. Treating with sulfur helps.

1. Yes, some varieties are more susceptible, especially those with some multiflora heritage.

2. Have the symptoms always appeared primarily on the oldest leaves? If so, it is not iron deficiency but magnesium or manganese deficiency. Iron deficiency always starts with the newest growth.

3. Or was the new growth susceptible for a while, but not now? If so, the warming and drying of the soil has made iron more available, and the pale leaves should green up gradually. In this case, you can expect a recurrence on these varieties next spring. You could apply up to a cup of sulfur per square yard now to prevent this by acidifying the soil, although I would want to check the pH first to make sure.

Looks like a tie, M_G.

Because it is affecting the older leaves and not the newer leaves I don't think it is an iron problem.

It could be a nitrogen deficiency, overwatering or spider mites. Some roses are more prone to these problems. Feed it with a high nitrogen fertilizer and check under the leaves to make sure there are no mites.

But nitrogen deficiency does not show a contrast with the veins. It shows as a general paleness across the plant.

Spider mites are a possibility. The lower leaves would show faint stippling as well as pallor with the veins greener.

Michael, you are absolutely right about the veins. My bad. I think we have ruled out Iron and Nitrogen. As you stated, Magnesium could be the culprit.

http://www.westone.wa.gov.au/toolbox6/hort6/html/resources/nursery/gvine/leaf_yellow2.htm

In my garden, whenever I see the yellow leaves with green veins it almost always due to overwatering. Spider mites on occassion do the same thing.

FWIW, Lyda rose is pretty intolerant of alkalinity. Mine gets sulphur all the time:-(.

Masha

This brings me back to my problem with light color leaves on my Pat Austin. I bought this rose and 3 others from David Austin about 4 years ago. I wonder if they all might be on multiflora root stock and that could possibly be why they have this almost peach color on their leaves. Well, Mary Rose does not but Eglantine, Pat Austin and WS2K do. They are in my various garden locations, some at home, some at my community garden spot. Does anyone know if DA sells on multiflora? They all grow very well - just not the dark green I see on pics of them on this website. I do plan on doing a soil test but this thread makes me wonder. If someone knows, please help. Thanks.
Mary

I've just been through this. Sounds like a magnesium deficiency. The cause may not be too little magnesium instead, it is probably a problem with the rose's uptake of magnesium. This can be caused by the soil pH being out of whack or an excess of potassium. The best solution is to foliar feed with chelated minerals. EDTA chelation is cheapest and most available but it only works over a narrow pH range. However, the plant can take up the minerals through its foliage. There are other, more expensive chelates but they only work over certain pH ranges. Miracid is a commonly available sorce of chelated minerals. Or there are liquid iron products-- just make sure they are chelated. You should do a soil test. Either send a soil sample to a test lab (most accurate way) or most garden centers have soil test kits--they are cheap but not very accurate, but they can tell you if your ph is too high or too low, or if your NPK is off.
For example I found that my soil has a high pH, high phosphorus and very high potassium. I'm now fertilizing with ammonium sulfate (21-0-0) and foliar feeding with chelated minerals and my roses are doing much better. I've now got deep green, healthy leaves and it seems that my rose blossoms have deeper color and more fragrance.
Be careful about adding just a single mineral (like epsom salts) The minerals in the soil need to be in certain ratios. An excess of one mineral can induce a deficiency in another mineral
Hope this helps.

Thank you for all the suggestions. I'm guilty of using a single mineral - epsom salts. I will try the foliar feeding. Can I expect the leaves that are showing yellow to green up or will it just be the new growth?

Subrosa, it's not clear to me that we have a diagnosis yet. If you could answer my questions 2 & 3. Basically, were the leaves old and lower when they turned pale, or did they come in that way as new growth at the top?

Another question, have you applied Epsom salts this growing season? If so, I doubt you could have Mg deficiency. It is taken up readily from the roots.

If the rose runs short of Mg or Mn, it pulls that element from the lower leaves in order to produce good new growth. In the case of iron, it can't do that, so the new growth comes in showing symptoms.

Rugosa roses and their hybrids are very sensible to lack of iron. And they like soils with a somewhat lower PH.
Landscaping roses seem to be far less susceptible to these issues.

everyrose hit all the important points. The first is that if a mineral (like epsom salts or iron) is applied the plant may still have problems with deficiency because the soil pH is CRUCIAL to the plant's ability to uptake certain nutrients. It was also pointed out that because of this a foliar feed can help.

The second was to point out that a soil test in order. It seems like a drag and an expenditure of time but because of the third point, RATIO, it is essential. Further, you don't want to be adding things to the soil that the soil does not need. Roses are just barometer's of your soil health or insect pressure.

Greenhaven, all true, except that

(a) it seems around 95% of mineral deficiencies in rose are iron deficiency;
(b) iron deficiency can be diagnosed definitively by looking at the plant;
(c) it's almost always related to pH, so there is an automatic prescription.

Its an important point that rose soils that have been fertilized for years are likely to have too much phosphorus and potassium.

Phosphorous and Potassium don't "move around" as much as nitrogen, right? I do wonder about something, though. I agree with the last statement you (michael) made, but do you think (or know) that there is a difference between organic and chemical fertilizers when it comes to excessive phosphorous and potassium? I know "blue stuff" over-fertilizing can lead to build-ups, but is the likelihood of this happening with organics lessened? I would think so but don't know so.

I am not trying to be contentious, just a disclaimer. But when you say "seems that 95% of deficiencies are iron deficiencies" can you provide documentation or is that anecdotal/experiential? Remember, not trying to pick a fight, just trying to expand my knowledge! :o)

I do disagree that iron deficiency can be diagnosed just by looking at the plant. Other deficiency symptoms range from "look similiar" to "nearly exactly the same." A soil test is still going to be the best way to determine exactly what the roses are lacking and what needs to be done to correct the situation.

Greenhaven, strictly anecdotal, based on posts here as well as my observations over a long period. I just made up the number. But iron deficiency is very common and all others are uncommon.

If you have pale leaves with green veins on the new growth, and without distorted growth, it is iron deficiency. So it's a pretty simple diagnosis to make, if people will just notice where the pale growth is occurring.

Greenhaven, your other questions.

Nitrogen is transient in the soil. It stays put as part of insoluble proteins until they are converted by bacteria to soluble urea (months/years). Then it passes into ammonium and finally nitrate. Unused nitrate washes out of the soil. But in natural systems it is almost all taken up and recycled into proteins. Organic ferts contain slow-release N mainly in protein form.

Potassium binds lightly to clay and decayed organic matter so it doesn't wash away. K in fresh organic matter is soluble and no different from manufactured sources. In mixed organic fertilizers, K is usually supplied by inorganic potassium sulfate.

Phosphate binds to clay. Also, it readily forms insoluble compounds with Ca, Mg, Zn, Cu, and Fe which don't wash out, and which can reduce availability of trace elements. In fresh organic matter and manure, there are organic P compounds that need to be broken down by bacteria. Bone meal and rock phosphate contain insoluble phosphates that must be cracked by acid to become available to plants. Superphosphate is soluble and plant-available, but it converts to insoluble substances over a period of weeks and stays put.

I don't think there's a difference between organic and inorganic ferts in the buildup of P and K. It just depends on how much excess potash and phosphorus we throw at the roses over the years.

I kinda thought that was the case, even though P and K are still readily available to the plants. Thanks for that!

Michaelg - sorry for not answering your specific quesions. The first leaves this spring showed the symptoms described from the bottom to the top. There are no spider mites.

We had a strange spring this year with a hard late frost. Many of the stems (on many different varieties) had to be pruned right to the ground level. Some had started to grow leaves and some even had flower buds when they suddenly turned black. However, the two varieties in question showed the yellow leaf/green veins in previous years so I don't think the cold weather is responsible for these symptoms.

I applied a weak Miracid solution a couple of weeks ago. In early spring I applied a handful of Epsom Salts, later a small amount of bagged manure. I rarely use commercial fertilizer and if I do, it would be 3-1-2. I try to avoid an excess of Phosphorous. Some years I scatter some green sand on the beds, hoping to increase hardiness.

There are about 200 roses in my garden and for the most part they grow very well. Of course, there have been a few that languished but they may have been too tender or growing in too much shade. Miniatures are a total failure for me.

Thank you for all your replies.

Subrosa, thanks for the details.

If you are growing 200 roses well, apparently your soil doesn't have any big problems. I would guess that either the two roses are especially sensitive to iron deficiency or their spots are a little more alkaline than the garden in general. It is common for iron deficiency to show worse in the spring flush of growth. You said the latest growth is OK, so they are able to find more iron in the warming soil.

Miracid actually doesn't acidify, but it does contain more iron chelate than regular MG.

If you want to prevent a recurrence, add up to a cup of garden sulfur per square yard to these plants and allow 1-2 years for the full pH change. If you want to green up the middle leaves, you could use an iron product from the garden center or continue fertilizing them with Miracid, say 1 TSP per week for a while and wet the foliage.

We have a lot of cane kill from the past winter. It isn't always immediately apparently with some of those canes. These do send out laterals, but the laterals are weaker and show yellowing just like you have described. I diagnose by cutting off the cane and looking for the tell tale yellowish, to brownish discoloration to the cross sectional surface of the canes. So, if some leaves on the same plant are healthy and some are yellowish and weak, consider this possibility.

cactus joe - Yes, I have had some of those just as you describe but the two roses in question are different in that the leaves are yellow with green veins. Plus, they have had this problem in past years.

One rose, Ravel, will probably be moved anyway because the color does not blend in with neighboring roses. It wouldn't cause me much concern except that it is growing in a prominent location. I will be sure to add the correct amendments when it is replanted.

Thanks for your suggestion.

Ravel is half multiflora, so that would explain it.