PH (GENERAL): Potting Media

Culture Orchid Doctor

by Robert M. [Bert] Hamilton (Compiler)

Originally published in The Orchid Doctor in 1980 and 1988

Posted by Sys Admin about 7 years ago.

Article Blog   Article Index
Acidity, alkalinity and orchids: the definition of pH; the pH scale; pH and orchids; control of pH, etc.jrefer to AU80-37+

Test for pH using litmus paper: soak several tablespoons of the media from an established plant in about three times its volume of distilled water for eight hours, filter it and measure the pH with litmus color kit. A80-229

Share on Social Media:  
Log in to Add a Comment

More The Orchid Doctor Articles under the Heading PH (General)

PH (General) Comments
PH (GENERAL): Adjustment How to bring it down to normal: do not use a sodium salt; the simplest thing is to use dilute phosphoric acid, at a few drops per gallon of water. A78-698 0
PH (GENERAL): Adjustment with Dolomite Limestone If paphlopedilums are growing in a medium of 6.3 or lower a light top dressing is recommended; if pH is 7.6 or more, repot the plant. A80-229 0
PH (GENERAL): And Acidity For results of tests, soil chemistry data, chemicals, availability chart of nutrients relative to a situation, refer to AU85(1)-10 0
PH (GENERAL): Buffering Most organic media have a high cation exchange and they buffer against nutrient and pH levels; for water, best growth follows the use of a pH level of 6 to 7. A85-1435 0
PH (GENERAL): Characteristics What pH is; its effects; the ways to change it; how to measure it; for a review refer to AU74-119+ 0
PH (GENERAL): Chemist's Term It refers to "potential hydrogen ion concentration"; it denotes the acidity or basidity of liquids of the soil solution; the neutral point is 7, acid solutions are lower than 7, basic solutions are higher; pH range for orchids runs from 5.5 to 7.5, 5.5 to 6.5 the optimum. A68-19; OR66-316 0
PH (GENERAL): Conditions; Growing Under Controlled Levels 4.5 to 5.0 is "very strong acidity" and 5.0 to 5.5 is "strong acidity" and are the leveIs at which orchids grow better; indirectly, pH affects the availability of the fertilizer elements to the plant; formulae for fertilizers suitable for cattleyas, phalaenopsis, and seedlings are given in detail with simplified substitutions offered; growth response reported outstanding; refer to A69-126+ 0
PH (GENERAL): Cymbidium Compost How to test for it: obtain a pH testing outfit from a scientific supply house, which includes a solution, color chart, barium sulfate, distilled water and test tubes; it has a possible accuracy rating of 0.7 to 0.3. A63-478The most desirable range is pH 5.0 to 6.0. A63-478; cymbidiums grow best with a pH of about 6.0 or 6.5; when a mix breaks down and the pH drops to 4.5 or 4.0 in two or three years the roots will die. OA78-100 0
PH (GENERAL): In Nutrition of Seedlings With a suitable medium, the growth and increments of weight of small plantlets are not affected by the initial pH. W9-67 0
PH (GENERAL): Meaning Alkalinity or acidity of a medium; 7 is neutral; values below 7 indicate acidity,- above 7, they indicate alkalinity; for orchid seed germination a pH of 4.8 to 5.5 is required; adjustments can be made by adding a base (alkali) or an acid. OBII-247 0
PH (GENERAL): Of Cymbidium Composts The pH of many components are given their pH ratings over a period of time in composts, the effects of alkaline water resulting in high pH; refer to AU81-102 0
PH (GENERAL): Of Fertilizer A pH8 to 9 of the 30-10-10 fertilizer is natural and should not be adjusted because the alkaline state changes to the acidic side when used by the plant. A81-27 0
PH (GENERAL): Of Potting Mix Experiments show that if a recommended medium is chosen the initial pH should cause no concern. Hort. revs. 1983-195 0
PH (GENERAL): Testing by a Cheap Method Buy an aquarium test kit, complete with test tube, color code; it is accurate to one-tenth of a pH point; and an indicator; cost is about a dollar (in 1969); test media or water. A69-403 0

New Topics

  1. kevan gregory asked question how difficult is it growing from seed in category General Discussion
  2. Carmen Britton asked question Information in category General Discussion
  3. Jeanne Uzar Hudson asked question Repotting Large Cattleyas in category Cattleya Alliance
  4. Nancy Shapiro asked question Where did you find this type of orchid pot? in category General Discussion
  5. Charles H Wood asked question Orchids wanted St.Croix usvi in category General Discussion

New Comments

  1. Carol Holdren commented on topic "Information " by Carmen Britton
  2. Carol Holdren commented on topic "Repotting Large Cattleyas" by Jeanne Uzar Hudson
  3. Carol Holdren commented on member plant C. lueddemanniana var. Coerulea, Venosa by Paulo Fiuza
  4. Jeanne Uzar Hudson commented on topic "Banrot 40WP" by Therese Stecher
  5. Maria Lucia Prieto Real commented on orchid Rlc. Village Chief Armani
  6. Mariana Chacon commented on orchid Gom. Jiaho Queen
  7. Roberto Lizama commented on member plant Max. dillonii by Roberto Lizama
  8. Nancy Speedy commented on scheduled event "2024 Orchid show Martin County "Ocean of Orchids"" by Martin County Orchid Society
  9. Jeanne Uzar Hudson commented on member plant Paph. Fanaticum by Jeanne Uzar Hudson
  10. R .Benson commented on member plant Den. Tianmu Green Elf 'Sweetheart' by R .Benson
  11. Alice Walker commented on article "Oeniella polystachys" by Tom Kuligowski
  12. Kathryn Kersey commented on scheduled event "Boca Raton Orchid Society Show & Sale" by Boca Raton Orchid Society
  13. BJ Lough commented on member plant Asctm. miniatum by BJ Lough
  14. Carol Holdren commented on topic "Where did you find this type of orchid pot?" by Nancy Shapiro
  15. Carol Holdren commented on topic "What is the culture for Cattliante Chongkolnee" by Mike Minney
  16. Linda Thorne commented on member plant Paphiopedilum Munchkin Mopsi Aru by Linda Thorne
  17. Carol Holdren commented on topic "Orchids wanted St.Croix usvi" by Charles H Wood
  18. William Gorski commented on topic "Is this a species or Primary Hybrid?" by William Gorski
  19. Henry Shaw commented on member plant Coel. Jannine Banks 'Snow White' by Henry Shaw
  20. Carol Holdren commented on topic "Trichocentrum luridum" by Danny Lyon