There is "no ambiguity in plant nutrition and nutrient " Well, until they can explain the vast interworkings and symbiotic relationships of soil microbes, and various plants and nutrient types they haven't even studied, I would say your claim is extemely over broad and one no real soil scientist would try to make. You seem to be intent on tying your implied position, because soil science says iron gets bound up in alkaline soils it can't be remedied with organic amendments to a "scientific principle" which doesn't go that far. You then attempt to use that overly broad claim of scientific unerpinning to determine that "acification" solved my problem. Really? How do you know that? It might have. You certainly can't know that as a scientific fact. Several other actions, or more likely combination of actions, probably contributed to the tree's vigor. 40 lbs of straight sulfer over the size of the area involved probably wouldn't have lowered the ph enough to overcome the bonding problem. The organic approach and trace minerals might supply, for instance, some microbial action that allows the binding effect to be lessened at the root level. Some microbes help plants generate nitrogen fixing at the root level, for instance. Microbes facilitate actions in the soil in ways large and small that we have little knowledge of or appreciation of at the moment. My personal guess is its less complicated. I just applied enough iron and trace nutrients to overcome the binding effect. The "get a bigger hammer" approach. And, quite to the contrary of what you claim, I don't suggest that people "dismiss everything soil scientist know". In fact, I did a lot of review of the binding problem they point out about iron and alkaline soils and various possible remedies before I tried the greensand. The best scientific answer I found was to drill holes and place iron supplements in the tree trunk. But, the studies suggested it had to be maintained, was costly and rarely had good long term results. NO studies (generally funded by chemical companies) suggested greensand, despite its high iron content and trace minerals. And yet it worked. Likely, in my humble opinion, just because of the volume. (As mentioned above, the "get a bigger hammer approach" is one that I usually don't use in gardening, but keeps working here.) As you can probably tell from my response one of my pet peeves is scientist who over state what they really know and can prove up scientifically. Like many on the global warming debate. We know something scientifically, the earth has been in a warming period of late, and then half baked psuedo science types insist we extrapolate from that scientific confirmation things like: therefore mankind did it, mankind has the ability to effect it, its definitely going to continue if we don't devote huge amounts of our economic resources to try to change it. Starting with one legit scientific observation doesn't give free reign to supply whatever next step one might be inclined to plug in UNTIL scientific trial and error has established it. But, like with most debates, just because you over state your position about what science "knows" in this specific inquiry, and doesn't, doesn't mean you are entirely wrong. I agree that its much better to not have to give supplements to a tree to keep it healthy. Whether by dry product, liquid or pellet form. If this wasn't already an otherwise nice tree in a location where I needed a nice shade tree, I probably wouldn't be bothering. But, since I inherited it and it takes about ten bucks and one act of "maintenance" a (or perhaps less if I experimented a little)to keep a tree that would cost a lot of money to replace with one of like size going strong, I think it well worth my time and money.

Goodness, how interesting all this is. I had no idea my simple question would call forth so much information and discussion. After reading and rereading these comments I went out and looked over my roses, then looked up pictures of rose foliage with chlorosis. Well. I don't know whether any of my roses have chlorosis. Some of them have some yellowing leaves, but I'm inclined to suspect a month without rain in full sun as the primary culprit. I don't see the pale leaves with darker veins that seem most characteristic of the disease, though I need to look more closely at the foliage on my plants. 'Trier' is nice and green. It's grafted on laxa, I believe, and perhaps this rootstock is adapted to alkaline soils? But I have a lot of Hybrid Musks on their own roots: 'Cornelia', 'Moonlight', 'Penelope', 'Thisbe', 'Vanity', 'Francesca', plus a couple of mysteries, and they all look okay. I developed a theory about my soil ph by seeing what grew and what didn't grow. No acidophile plants grew: not a one: no camellias, no rhododendrons, no blueberries. Kerria japonica is a rare exception, but it does get chlorosis at times. On the other hand, the plants that do grow well for me are the ones the Hillier guide to trees and shrubs says are good over chalk: barberries, buddleias, box, eleagnus, euonymos, forsythia, bay laurel, ligustrum, lonicera, mahonia, mock orange, etc. etc. Not that we have chalk, but chalk soils ought to be alkaline. (Correct, Ann?) Our soil is gray clay that's concrete when dry and glue when wet. So I don't know what's going on. Is there some other reason I can't grow acidophile plants aside from soil ph? Do these plants mostly hate clay? Do they have to be watered, but loath the water we have to give them? There are other plants I have trouble with for unclear reasons: Osmanthus (tea olive)is one. As for the roses, is the soil just not alkaline like I thought? Or do the roses love the tons of compost, hay and practically nothing else, that we give them? Do they actually benefit in some respects by not being irrigated?? Are their seasons of growth such that they are most active in periods when soil conditions favor the uptake of iron? Or is there some chlorosis and I'm just not familiar enough with it to recognize it? I know I could get the soil ph tested, but this is more fun. Technology offers benefits, obviously, but it can never take the place of looking and thinking. Melissa

Sherry, have you tried shredded redwood bark? It's often sold in garden shops under the name 'gorilla hair bark'. Redwood bark is slightly acidic, and I use it to mulch my flower beds that contain roses. My mother used redwood bark in her rose garden, and I remember the distinctive smell of the redwood. Today if you go to a garden center they have plenty of bark chips, usually small to medium chunks, and some of it is red *colored* but it isn't redwood, and is sometimes even dyed red. Don't know what the ph would be on wood of unspecified variety. I bought Reines des Violettes in February of this year from Greenmantle (northern California nursery) and planted it in my garden. Heard warnings that it gets chlorosis. But so far no signs of it at all in my garden, and I haven't added any sulfur, iron, or acidifying plantfood. But I did mulch it, along with my other roses in redwood bark. Perhaps the water percolating through the redwood is acidic enough for this rose. Don't know. But I went out yesterday and snapped a few pictures of the leaves of my Reines des Violettes. She seems to be doing just fine. Would be doing even better if the tree trimmers (who removed 3 huge trees for me!) hadn't dropped a big log on her bigger half and smashed it off. However, she's recovered nicely. Melissa Here is a link that might be useful: Leaves of Reines des Violettes

Hi and Welcome! I've never seen chlorosis like that, the leaves are almost white. I also suspect you are overfeeding from pictures of the burnt leaf edges. I've grown carambola, was too lazy to feed anything...and they seemed to do fine. For young seedlings, I recommend being on the conservative side w/fertilizers.