Cheapest way to test soil pH using red cabbage
My limestone clay, pH 7.7, keeps the surface dry and alkaline, resulting in no-spray garden with clean roses. Soils that lack calcium often result in balling, botrytis, and weaker cell walls, which are susceptible to fungal diseases. Calcium, potassium, and phosphorus are all essential for strong root system.
Best to test your soil pH and tap water, before you add gypsum. There are other types of calcium if your soil is acidic, posted in the thread, "Types of Calcium ...."
Chop 6 leaves of red cabbage leaves, boil in 2 cups of DISTILLED water, use the hot juice and pour on top of samples of soil taken from your garden, wait for 20 minutes, if the juice on top is clear: neutral. If pink: acidic soil. If blue: alkaline.
Also boil some red cabbage in your tap water, if it's way-more blue than the red cabbage boiled in distilled water, then your tap water is alkaline. The pH of my tap water is 8, and Annie L. McDowell rose hated it. I had to lower my tap water with citric acid.
Citric acid is sold at the Health Food store, 1 lb. for $10, sold for sprouting. Roses root better if the pH of tap water is brought down to 5.6 as in rain water. I no longer use vinegar nor used lemon to bring down the pH 8 of my alkaline tap water (burns in hot weather). I find that a tiny bit of gypsum (calcium sulfate) neutralizes the bicarbonates (hydrated lime) in my tap water.
Below is Annie L. McDowell rose, 100% thornless, great scent that smells like lavender/lilac. It has the strongest scent among the 70+ roses that I grew for the past decades (I'm down to 55 roses now).
Annie is a musk, prefers slightly acidic. To prevent balling, I fertilized Annie L. McDowell rose with gypsum (calcium sulfate). Picture taken late May, after died down to few inches due to mid-April snow in my zone 5a.
Here is a link that might be useful: Cheapest way to test soil pH using red cabbage
This post was edited by Strawberryhill on Sun, Sep 29, 13 at 11:21