Malcolm: thanks for the info. on pH meter. I checked on that before, and found that most of them are not accurate, and even the more expensive one above $200 need to be re-calibrated before each use. Red cabbage boiled in distilled water is quite accurate, since I am testing one agent against each other: color of Miracle-Gro potting soil is very pink, against the color of Scott's premium top soil with peat moss (greenish blue). I checked the colors of all 10 samples after 1 hour: peat moss gets even pinker, Scott's premium soil gets greener. Reg_pnw7: thank you for your feed back, my goal is to learn, and I don't need to be right, since I'm a newbie. Corn meal tested neutral, and the color of red cabbage boiled in my alkaline tap water is bluish purple, compared to the color of red cabbage boiled in distilled water, pinkish purple. If you google "optimal pH for fungi growth", there are several that cited preferably acidic for fungi growth. The red cabbage boiled in distilled water is an interesting experiment to test various materials. Try it and you'll see how accurate it is by testing with at least 10 mediums: few drops of vinegar, coffee ground, peat moss, baking soda, MiracleGro potting soil versus Scott's bagged top soil. The peat moss and MiracleGro potting soil get more pink after several hours, and the Scott's get more green. I used quite accurate fish tank litmus paper (Jungle brand from Walmart). It correctly gave a 7 for distilled water, and a 8 for my tap water. The direction said to read within the first minute - it took more than 10 minutes to get the epsom salt to dissolve, and this gave a more alkaline false reading at pH 7.3 to 7.5. However, when epsom salt is tetsted with red cabbage, this gave a correct neutral pH: the color did not changed compared with the control red cabbage boiled in distilled water. Blackspots can germinate on the ground and get splashed up by rain water. This year I have zero blackspots on 10 Austin roses mulched with very alkaline horse manure, as recommended by the British.

Hi Prairie_north: Very pretty bloom on your mini-rose. Thank you for the l info. that cracked corn changed from pink (acidic) to purple (neutral) fast. I'm happy with cracked corn in the planting hole (did that last year), so is Momscottagegarden (clay soil). I like what you wrote: "The bed around it was originally amended with peat moss, and has cedar shavings on top. Today I pushed the shavings away, dug up the soil around it, put down some sheep manure, and red lava rock." Peat moss mixed with clay becomes hardened a year later. Cedar shavings is acidic (pH 4) that would leak acid down when it rains (pH of rain is 5.6). Since mini-rose is own-root, the roots are nearer the surface, and is sensitive to acid leaching down. Own-roots do best with organic fertilizer, since it's nearer the surface ... some are wimpy like alfalfa sprouts, versus big-woody-bush-trunk Dr. Huey. Red lava rock is a strong buffer at pH 8. I mulched roses with that during our wet months .. kept roses clean. Blooming takes up lots of potassium & calcium to make those firm petals. After blooming, potassium and calcium are both depleted, plus rain leaches out potassium & calcium & trace elements. Red-lava rock in the planting hole, plus on top provide a continuous supply of potassium to prevent diseases, plus more blooms. Calcium is a strong buffer: I use that in many ways: as granular gypsum (calcium sulfate) to break up clay. If it rains a lot, I put gypsum on top of red-lava-rock. But for Dr. Huey-rootstock, I put dolomitic lime on top, since Dr. Huey likes it alkaline. Best ratio in hydroponics setting is equal nitrogen to potassium, 1/2 phosphorus, and 1/2 calcium. I burnt a few own-roots with either salty manure in hot weather, or high-phosphorus fertilizer like bone meal. My best result in hot weather is alfalfa hay for nitrogen. Timothy hay is much softer, easier to mulch .. that's what I plan to test next. I got amazing result mulching with alfalfa hay in hot weather, best nitrogen-source ever, which beat anything I tested: blood meal, compost, Milorganite, alfalfa pellets, alfalfa meal, corn meal. The problem with alfalfa in smaller particles: they gunk up on top, either souring, or hardening clay further. Alfalfa hay is fluffy, which cools and shade the roots in hot sun, plus it's a strong buffer: neutralize both acidic rain, and alkaline tap water.

Hi Sharon: You benefit me & others with your intelligent questions, which enable me to see what I did wrong with my past experiments. How did I cause rust by throwing POWDER GYPSUM on top? I repost the info: There's a U. of Nebraska research on rust, with the title, "Medium pH and Leaf Nutrient Concentration Influence Rust Pustule diameter on leaves of dry beans." Their conclusion: Plants grown in pH 5.8 medium show significantly larger rust pustules than plants grown in pH 6.5 or pH 7.9. Concentrations of Cl (chloride) and Mn (manganese) were more in high rust. In contrast, concentration of K (potassium) were less in high rust." From Straw: Alabama Agriculture Cotton Research also recommended potassium fertilizer to reduce rust. Info. about gypsum from USAgypsum.com: Elemental Calcium......21.0% Elemental Sulfur (S)....17.0% pH...................................6.8 Kelp4Less sells 5 lbs. of GRANULAR GYPSUM at 18% sulfur for $12.50 .... more than my local feed store, or Menards at $4.49 for 25 lb. bag. There's a quarry nearby that manufactures gypsum, so cheap here in my Chicagoland. I WOULD NOT use Pennington gypsum plus lawn fertilizer, if it's chemical nitrogen (high in salt). What I did wrong was to throw 1 cup of POWDER-gypsum on top ... it's acidic, plus fast release of calcium, which drove down potassium, necessary for rust-prevention. Previous times with 1/8 cup of GRANULAR gypsum, along with sulfate of potash ... no problems whatsoever. I would use even less GRANULAR gypsum, like 1 teaspoon, along with 1 teaspoon sulfate of potash, plus 0.2 cup of Milorganite. The best ratio for veggies is 1 part nitrogen, 1 part potassium, and 1/2 part calcium. Roses have a higher need for calcium, so I use equal amount to potassium. Sulfate of potash NPK is 0-0-50, and Milorganite NPK is 5-2-0. Take 50 divide by 5, you'll get 10. Ten teaspoons of Milorganite is equivalent to 0.2 cup, best with 1 teas. of sulfate of potash, and 1 teas. of gypsum. I would use more sulfate of potash & gypsum with pale own-root like Jude which needs more potassium for blooming, plus more sulfur for leaves to be darker-green. PALE own-root like Duchess de Rohan, W.S. 2000, Jude, Eglantyne, Honey Bouquet, Comte de Chambord can take more gypsum at 17% sulfur, and more sulfate of potash at 23% sulfur. DARK green roses grafted on Dr. Huey, and French roses dislike acidic sulfates. Bone meal has high sulfate at 2000 ppm, and 400 iron & 300 sodium, with the dark-green roses break out in diseases. I put too much bone meal in Gruss an Teplitz hole ... he's the parent of Dr. Huey, it became a BS-fest, and I had to fix the hole. Pennington fish pellets NPK 4-6-6, high phosphorus with fish bone meal. The pale & lighter-green roses LOVE that tea, today tiny Jude broke out in 2nd flush, 3 more buds with that tea, very fast repeat. Austin roses, bred in an acidic & high rain England like that ratio ... The ratio in David Austin Rose food has NPK 9.5 - 7.5 -10 ... a bit higher nitrogen due to high-rain England, which leaches out nitrogen. Acidic sulfates help pale-own-root to bloom better, but sulfates also burns if in direct-contact with roots, best as SOLUBLE. Pennington pellets is best as SOLUBLE tea under hot sun, to spoon-feed wimpy own-roots which can't acid-phosphatase as band-size. Bone meal is OK for pale own-root the planting hole, if mixed-thoroughly and buffered by plenty of soil. Bone meal burns if applied on top. Concentrated amount of sulfates near the stem burn. One person killed his tomato plant by topping with Jobe's Organic tomato fertilizer NPK 2-7-4, high in bone meal. When I mixed that stuff THOROUGHLY in the planting hole, I got bumper-crop tomato. Same with gypsum, at 17% sulfur, and sulfate of potash, at 23% sulfur. Both burns my finger, and burns any root, best used as soluble. If I sprinkle some on top, I flood the basin immediately with water, to dilute that, along with milorganite for nitrogen. Tomato Tone has NPK 3-4-6, neutral pH & less phosphorus ... it didn't burn my tomato plant, so that can be applied at 1/4 cup before a rain. It's finer particle & tend to float, best to let rain work that in. Milorganite is best 0.2 cup with 1 teas. sulfate of potash and 1 teas. of granular gypsum .... spread that on top before a rain, if you are lazy like me. Safe approach would be Milorganite on top, then make soluble out of potassium & calcium per gallon of water. Roses are all different from each other, the pale ones require more sulfates, potassium, and phosphorus via SOLUBLE to bloom. The darker-green leaves like Dr. Huey can secret acids to utilize nutrients from soil, thus breaking out in diseases when too much acid is supplied, like rain-water (pH 5.6 in East coast), or sulfates in bone meal, gypsum, and sulfate of potash .. which are components of Pennington Pellets. Sharon, best wishes with your roses. They all are different from each other ... such as pale Graham Thomas which required an ungodly amount of potassium & phosphorus as soluble to bloom for a Texan. It took me 3 years, and countless failed experiments to learn the above. This post was edited by Strawberryhill on Sun, Jul 20, 14 at 11:19

Sharon: THANK YOU FOR THOSE FANTASTIC PICTURES !! I also did red-cabbage test today Sat. 7/25/20. Distilled water boiled in red cabbage is actually acidic according to on-line info. "Pure distilled water should be neutral with a pH of 7, but because it absorbs carbon dioxide from the atmosphere, it's actually slightly acidic with a pH of 5.8." From your pictures above, the grayish blue solution is alkaline with pH 7.5. My pH 7.7 clay is a bit bluer (tested by Earth Corp. soil testing company). Black, gray, or clear solution is neutral pH .. means it's a fantastic buffer (good for plants). I tested COMPOSTED grass clippings and it's clear water above black solution. Buffer is great to neutralize the acidity of rain. Clay buffers better than sand/loamy soil, but the best buffer is composted organic matter. Coffee is also a buffer (at first pinkish, but after 20 min., it's a clear solution). COMPOSTED plant-matter is very alkaline and neutralizes acidic rain well. COMPOSTED leaves decompose to alkaline pH, when I stuffed a bunch of leaves in LOAMY & fluffy soil .. the next year that got converted into HARD CLAY, very alkaline. Green grass clippings stay fluffy longer (more nitrogen & more acidic). Brown leaves are considered "carbon" in a compost pile, and decompose to alkaline pH & hard like clay. My tap-water in red-cabbage is VERY BLUE, it's at pH 9 as stated on village's website. I also tested baking soda and it's more blue than my tap-water. I tested paver's sand or yellow coarse sand, and it's slightly alkaline. I tested composted manure and it's very alkaline (from the lime added to deodorize and kill weeds in the bag). The pH of composted manure is just as alkaline as my clay at pH 7.7. Your LAST pic. is slightly acidic. Rain-water is even more acidic & reddish purple. Rain water here is pH 4.5. I also tested some drops of vinegar and it's fuchsia red around pH 3. All my rooting-soil for cuttings are black or clear solution at neutral pH (they have lots of yellow sand or vermiculite mixed in). The clay taken from diseased & black spotted roses are slightly acidic, rather than blue like my pH 7.7 clay. I had tested 5 different roses with black spots in the past, and the soil taken from the root level is pinkish in red-cabbage juice. It's either acidic rain can't drain well from that spot, or else there's NOT enough buffer to neutralize the heavy rain going down.