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strawchicago

Make leaves thicker & stronger with calcium and potassium

strawchicago z5
10 years ago

Paul Neyron was naughty when I gave him acid-fertilizer high nitrogen: He blackspotted and blooms balled up. Then I moved him into partial shade, with Ball's Potting soil: composted fine pine bark (has tannin, a fungicide), peat moss, perlite, vermiculite, lime (fungicide) , and gypsum (calcium sulfate). He's healthy, see below:

Calcium is best together with potassium. Here's an excerpt from Missouri State: "Calcium is an extremely important mineral in plant nutrition ... Calcium is also important in root development."

My soil is limestone clay and my soil test came back "barely adequate in calcium!" I grew roses in acidic clay before, they had dark-green leaves, but very thin. It was a blackspot-fest then even with Bayer spray.

Both calcium and potassium STRENGTHEN the cell-membrane of plants, to prevent fungal invasion. Calcium spray is used for botrytis, and prevents balling. High nitrogen and high potassium drives down calcium. High nitrogen results in balling, or disfigured blooms without adequate calcium. Calcium nitrate is recommended for sandy soil or pots, where nitrogen leaches.

For tomatoes, Ohio State University stated: "Blossom-end rot is a physiologic disorder associated with a low concentration of calcium in the fruit. 1.Maintain the soil pH around 6.5. Liming will supply calcium 2.Use nitrate nitrogen as the fertilizer nitrogen source. Ammoniacal nitrogen may increase blossom-end rot as excess ammonium ions REDUCE calcium uptake.

Calcium and potassium maintains osmotic pressure, so plants don't get droopy in the heat. Best used together. Kelp4Less sells both: soluble gypsum and sulfate of potash ... free shipping, best used as soluble.

Below link is the procedure to get your soil pH FAST by using $1.50 worth of red cabbage and distilled water. If your soil pH is acidic, calcium and potassium is less available.

See below picture of how thick and rigid the petals of Radio Times and Mary Magdalene (white) get when I dunk calcium citrate in the vase to prolong its vase life.

Here is a link that might be useful: Cheapest way to test soil pH using red cabbage

This post was edited by Strawberryhill on Sat, Oct 5, 13 at 22:01

Comments (7)

  • Krista_5NY
    10 years ago

    Beautiful roses, Strawberryhill. Thanks for the info on pine bark, tannin and calcium.

    I hadn't realized that pine bark contained tannin.

    That's interesting about calcium and cell membranes. Calcium is a micronutrient for roses, good to know how it works for the plant.

  • strawchicago z5
    Original Author
    10 years ago

    Thank you, it's so refreshing to hear your kind words and vast experience of growing hundreds of rose for decades in your zone 5a NY garden.

    Mike_Rivers, a retired chemist from MI, stated that he's trying spraying with milk. Milk is high in calcium, so it acts like a foliar spray to strengthen leaves. Milk has salt, which inhibits fungal growth.

    Applying gypsum (calcium sulfate) in my pots make a big difference, they are perky, thicker leaves, and less watering.

  • strawchicago z5
    Original Author
    10 years ago

    Looking at the 2 bouquets picked today, Sept 10, at 93 degrees ... I can tell you which one is fertilized with soluble calcium (gypsum). The blooms have firmer petals, more photogenic, and last longer in the vase with added calcium. They are: tiny dark pink Yves Piaget's child, Pink Peace and mauve Wise Portia (both calcium and potassium added).

    There are several studies that showed plants can withstand heat and drought better with calcium and potassium.

    This post was edited by Strawberryhill on Sat, Oct 5, 13 at 12:01

  • strawchicago z5
    Original Author
    10 years ago

    I found a horticultural abstract entitled, "Applications of Potassium silicate decrease black spot infection in rose Fuschia Meidiland". The conclusion: "The results indicate that using potassium silicate in irrigation water may be a useful component of a disease management system."

    Potassium silicate is a pH up, it makes the soil alkaline and imparts silicon to the leaves. Potassium silicate is sold as "Rhino Skin" for $7 at Planet-Natural .. I wonder how they extract that from Rhino Skin?

    http://www.planetnatural.com/product/rhino-skin-potassium-silicate/

    I googled "Foods highest in silica" and found this info: "one of the best food sources for silica is oats. A breakfast muesli made with raw soaked oats eaten daily supplies lots of silica. (Guess why horses fed with oats are so strong and have such shiny coats?) Without silica there would be no lustre to our hair; we would have brittle nails, rough and itchy skin and no elasticity in our connective tissues."

    I got 42 oz, or 2 lb. of oats for $2 at the grocery store. I grounded that up in a coffee grinder, and fertilized Bolero, very pleased with the results ... cheaper than Rhino skin!

    Here is a link that might be useful: Horticultural abstract on potassium silicate

    This post was edited by Strawberryhill on Sun, Oct 6, 13 at 11:47

  • strawchicago z5
    Original Author
    10 years ago

    Oats is high in manganese ... most deficient in my alkaline clay soil. My clay is tested exceedingly high in magnesium ... magnesium is what makes clay sticky. Here's an excerpt from the below chart on nutritional deficiency, taken from a cannabis site. Note: I don't do drugs, I only grow roses, but the site is helpful in identifying nutritional deficiencies:

    "MANGANESE (Mn) Necrotic and yellow spots form on top leaves. Mn deficiency occurs when large amounts of Mg (magnesium) are present in the soil. Foliar feed with any chemical fertilizer containing Mn."

    POTASSIUM (K) Affected plants are usually tallest and appear to be most vigorous. Necrotic spots form on lower leaves. Red stems. Leaves appear pale or yellow. Add chemical fertilizer containing K."

    Here is a link that might be useful: Nutritional deficiency table

  • bluegirl_gw
    10 years ago

    LOL, Straw! Great information source!

    No, seriously, it IS a good table. Just laughed when I saw the source. Some of the most useful info. I've found on all sorts of growing things comes from such sites. All the stuff on using cloners, hydroponic gardening, growing supplements--you name it--the pot growing sites are the best.

  • strawchicago z5
    Original Author
    10 years ago

    Hi Bluegirl: I'm glad to hear from you, thanks. I wish I had seen the above info., before killing my rhododendrons with iron sulfate. Later I found an Illinois field study with pine trees, reporting that my area is deficient in manganese (diffused yellowing), rather than iron (well-defined green veins on yellow leaves). Deficiency of manganese often result from compact, poor drainage clay.

    What I should had done was to buy $2 worth of wheat bran or rice bran, highest in manganese. See info:

    "Wheat bran provides 6.7mg (334% DV) per cup, rice bran provides 16.8mg (838% DV) per cup, and oat bran provides 2.1mg (106% DV) of manganese per cup. "

    .... or better yet I should had dug up my acid-plants and fixed my heavy clay with coarse sand and coarse pine barks (pH 4.5), after the acid-fertilizer and the iron sufate failed.

    Here's a picture of manganese deficiency in heavy & compact alkaline clay. It's very common in my pH 7.7 clay:

    http://www.ipm.iastate.edu/ipm/hortnews/2006/8-23/deficiency.html

    Here is a link that might be useful: Top 10 foods highest in manganese

    This post was edited by Strawberryhill on Tue, Nov 5, 13 at 17:00

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