Thanks to everyone for the interesting responses. dirtydan, have you had a soil test done to determine why your pH is so high? Unfortunately there is no one in this area that will do a soil test for less than $70 per sample. I recently found a link to University of Mass Amherst that offers soil tests for $13 so I am planning to send them some samples. http://www.umass.edu/plsoils/soiltest/soilbrochure2009.pdf I use home test kits for nutrient and pH. I also have a Hanna pH meter that comes in handy for quick tests. I don't know my native soil composition. Its pretty bad though. It could be described as dense gray clay with some occasional small pockets of white material. When dry, its is normally cracked and coated with a layer of frosty looking crystals that taste like salt. The salty crystals grow up the side of masonry, concrete and stucco walls. When wet, it turns to a slippery slime that will coat the bottom of your boots with a couple pounds of thick clay. It has no vegetative matter whatsoever. I have been prepping my raised beds with compost, sand, clay, fertilizer and various sulfur products to lower pH. Where are you in the Mojave? I am located in the city of Lancaster, CA. This is the high desert north of Los Angeles at about 2,400 ft elevation. We only get about 5 inches of rain per year, most of it is in February. In fact we will probably not see any significant rain here until next fall or winter. The arid conditions are one of the reasons for the high soil pH and lack of organic mater, also the fact that we are almost entirely dependent on alkaline municipal water for irrigation. What are you trying to grow that is having trouble? When I first moved here I put tomatoes, squash, cucumber, melon, and several others in the unamended native soil. They were all killed or stunted from the salt or nutrient deficiencies. Iron chlorosis and micronutrient deficiencies were evident in the plants that didn't die immediately. The only exception were some tomatoes that I managed to save by side dressing with aluminum sulfate and a highly acidified nutrient solution, they remained quite stunted however and suffered from BER. Since I have built raised beds and worked the soil, I have a productive garden and only seem to have problems with cucurbits in beds that have been freshly sulfured, and typical aphid and leaf miner infestations. There are two main reasons as to why sulfur is the preferred material for acidifying soil. 1. Economics Sulfur is one of the most plentiful and inexpensive elements on earth, said to comprise 2% of the mass of the earth. Sulfur is a byproduct of oil and gas refining and there is a massive oversupply of the material, especially in Canada where its is extracted from oil sands during refining. High concentrations are not toxic to vegetables. Cucurbits being the exception. Avoid sulfur contact with the leaf surface of cucurbits. Other possible acidifying agents (some impractical): ammonium nitrate liquid nitrogen urea diammonium phosphate acetic acid hydrochloric acid HCl (also called muriatic acid) phosphoric acid Elemental sulfur has been used for centuries as a fungicide and miticide. I don't know if, or to what extent, it affects beneficial soil fungi. I suppose that a reduction in soil fungi is OK as long as our vegetables are not negatively impacted, and there is no damage to the environment. Once the sulfur it oxidized by soil bacteria I would speculate that soil fungi will return to pre-application population size.

Berndoodle, *** I assume you've dug down 6 or 8 inches in the soil about a foot out from these roses and tested the dampness of the soil? I will dig down and check for dampness. All the roses get the same watering (more this year than last) and lots more rain this summer than last. *** What else do you know about your soils? Compacted? Organic matter content? Organic matter in the soil acts as a warehouse for nutrients and moisture. Organic mulch... The original ground is mostly very compacted gray sandy stuff with limestone rocks and strands and chunks of white clay. I dug down to about 15", removed half of it and all the rocks and 90% of the clay, replaced it with bagged topsoil & composted cow manure, pine fines & composted horse manure. In May I mulched with newspaper (long gone), CHM and pine straw. When I removed Duchesse de Brabant, I was amazed by the thick roots that went pretty much straight down. A couple of them were 2.5 feet longer where they broke, so they're going down into native ground which is yucky. And who knows what THAT pH is! My amended soil was in the range of 6.8 to 7.0, but I haven't checked it recently. All the roses get the same treatment, but some are reacting differently. Last year in his first summer Mons Tillier was well foliated and wonderful. This year he's huge (6+ x 6) but almost no leaves inspite of more water and MiracleGro in August, September & early October. (Thanks for the suggestion, Taoseeker.) His roots have to be deep down is the crummy stuff by now. On the other hand LeVesuve is in a bed that probably didn't get as much good stuff to balance the awful native stuff as MT did, and it's lush and blooming big (but no where near as tall as MT since he was moved this March.) Anna Olivier is located in or very near the road bed (really crappy stuff almost like hardpan) prepared the same way but she's beautiful and lush. Saldut, my azaleas grow better in builder's sand than the native soil, but all the builder's sand is gone. Ann, if it were just water that would be an answer anyway. The last several days I've been watering daily by hand but not heavy with the hose. It's been very dry since summer ended 10 days ago, plus some areas need more mulch. When I check them down at 6" or 8" depth, I'll know if I'm watering enough. Old Blush is surviving but that's about it. She's looks like she should be living in an abandoned cemetery. Even though my pH near the surface isn't real high (high enough that multiflora-blooded roses don't like it), these roses are supposed to like pH around 6.5 or less, right? So I was wondering if they really hate putting their roots down in the deadzone below. My theory is that for the first year they're loving my amended soil; then after that they're suffering in the native stuff. Sherry

Hi Lyn: I'm glad to hear from you (I miss you, honestly). I posted it in Robert's English rose forum, see the link below. The advantage of red cabbage juice test, which toxcrusadr (a chemist) in the soil forum thinks its a good idea, is: It's more accurate since you can put a large amount of soil, rather than 1 teaspoon like those test-kit sold for $12 at the stores. As the soil soaks in the red cabbage juice for more than 20 minutes, it allows time for elements in the soil to be released. For $1.50 cents (99 cents of distilled water and 50 cents of red cabbage), I can test 10 different samples from various places in my garden, or different bagged soil products, to see which one most alkaline. I used those small plastic applesauce cups to hold samples. When I first tested coffee grounds from my Hubby in red cabbage juice, it was pinkish like acidic potting soil. After 1 hour, the solution was clear at the top, not a single pink trace left. Coffee is a buffer, it neutralizes the soil, as Michaelg informed. I topdressed roses with coffee ground with no problems. Espresso ground from Starbucks is different: it stayed pink and gave my rhododrendrons pink stripes. One pot has MiracleGro Organic potting soil, neutral pH. At first Sonia Rykiel was dark green, but after 3 months of akaline tap water at pH of 8, she became very yellow. I tested her soil again in red cabbage juice, same color as my soil (pH 7.7), bluish green. The fish-tank litmus strips sold at Walmart for $5 is a fast way to test one's water. It's more accurate in the alkaline range, and NOT so in the acidic rain. I would NOT use it to test the pH of rain water, reported at 5.7, which explains why the roses in my alkaline soil are dark green in the spring. Here is a link that might be useful: Test soil pH for $1.50 using red cabbage

Hello, tinamcg. I do not try to change hydrangea color but this is my understanding of the process. Before adding aluminum sulfate, I would make a soil test. A soil test is necessary to tell you if you already have "enough" naturally occuring aluminum in the soil. If you do not then apply aluminum sulfate to increase aluminum levels and lower the Ph. Aluminum sulfate should work fast since its application causes a chemical reaction. Once you measure "normal" levels of aluminum in the soil or if you already had "normal" levels of aluminum in your soil, you may want to apply elemental sulphur (a.k.a. flowers of sulphur) in order to further tweak the PH Level. Contrary to aluminum sulfate, Elemental Sulphur takes several weeks to acidify the soil because it first has to be oxidized by bacteria (here you have a biological reaction, not a chemical reaction). I would add chemicals monthly but only thru the growing season in Spring and quit when summer starts. Not particular reason for that though. I do not want to introduce 'problems' with the addition of chemicals at a time when the plants experience high temperatures, lack of humidity and drying winds. Regarding your desire to control the color to lilac or blue, be aware that color change is a project that takes several years and requires lots of applications and soil tests (to see how things are progressing). Also, it is very difficult to the intensity of a color (how strong or pale the color is) so you may need to experiment with other varieties if ES just does not want to attain the type of color that you want. Luis