FERTILIZERS: How to Read a Fertilizer Label

Culture Orchid Doctor

by Robert M. [Bert] Hamilton (Compiler)

Originally published in The Orchid Doctor in 1980 and 1988

Posted by Sys Admin almost 8 years ago.

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Interpretation of wording of guaranteed analysis labels for water-soluble 27-9-18, somewhat slow-re lease 27-6-10, slow release for cymbidiums 6-9-6, water-soluble 10-10-5; refer to A71-30+
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Fertilizers Comments
FERTILIZERS: 30-10-10 Recommeded instead is 20-10-20 called Peters' Peat Lite Special, apparently better because of its nitrate nitrogen, instead of the more common ammonium nitrogen from urea. OIE86Sept. 0
FERTILIZERS: 30-10-10 for Plants in Tree Fern and Redwood Bark The formulation is suitable the year round. A73-991 0
FERTILIZERS: 30-10-10 with Soil Acidifiers and Chelated Iron A suitable fertilizer, use 1/2 tpg. at every watering but let 10% of the liquid run out of the pot for leaching action. A74-114 0
FERTILIZERS: Applied to Pots Containing Various Potting Mixes If 30-10-10 is used it can be applied to bark mixes and tree fern mixes generally. A69-793 0
FERTILIZERS: As Pot Surface Dressing, What Is Safest? Liquids are safeest and are effective. A79-370 0
FERTILIZERS: Balanced It provides nutrients in these ratios: 1 molybdenum, 60 copper, 200 boron, 200 zinc, 500 manganese, 1000 chlorine, 1000 iron, 10,000 sulphur, 20,000 magnesium, 20,000 phosphorus, 50,000 calcium, 100,000 potassium, 140,000 nitrogen. AU84-278; to convert 20-20-20 to 2-2-2, use one-tenth of the prescribed amount. A81-1311 0
FERTILIZERS: Basic, to Mix with Media To 1 cu. yard of mix add 1.5 kg. of potassium sulphate, 1.0 superphosphate, 1.0 dolomite lime, 100 grams fritted trace elements, 250 grams iron sulphate, or 60 grams iron chelate; slow release fertilizer can be substituted for the first three. AU79-51 0
FERTILIZERS: Best After Test Levels of fertilizing on cymbidiums which gave best results were N -- 100ppm., P -- 20ppm., K -- 75ppm., Mg (Magnesium sulphate) 25ppm., and Fe (Chelated Iron) 8 to 10ppm.; these represent very weak strengths but produce remarkable growth rates. AU84-199 0
FERTILIZERS: Best for Cymbidiums In an experiment in Southern California a balanced 20-20-20 produced 50% more spikes than 25-10-10 at the end of two years. OA84-78 0
FERTILIZERS: "bloom Booster" Application should alternate every two or three feedings in a mixed collection with one of high nitrogen but the frequency should be reduced for winter. A85-872 0
FERTILIZERS: Cattleyas Use 30-10-10 in bark or Mexican tree fern. A79-124 0
FERTILIZERS: Characteristics Table of ratios for 10 commercial fertilizers giving fertilizer materials, fertilizer ratios, application rate, pH values. P68(3)10 0
FERTILIZERS: Color of Liquid Stock Solution Two good dyes are available, malachite green and potassium permanganate, available from drugstores; takes very small amounts to color a solution; experiment with quantities to establish a ratio in the stock tank. A60-128 0
FERTILIZERS: Controlled Release Types Osmocote with nine months release rate is improved upon with an extra liquid fertilizer solution from Spring onward, especially if the seedlings had been placed in a larger pot size to begin. AU82-106 0
FERTILIZERS: Determining Ph Value Mix one part fertilizer to one part water and let stand for an hour; test with pH tester. P68(3)10 0
FERTILIZERS: Dry Soluble Types These are best; there is no point in packaging, transporting or storing water. OD67-220 0
FERTILIZERS: Element Requirements for Cattleyas N -- 50 ppm., P -- 50 ppm., K -- 50 ppm., plus Magnesium Sulphate -- 50 ppm. AU82-98 0
FERTILIZERS: Element Requirements for Most Other Than Cattleyas N -- 100 ppm., P -- 20 ppm., K -- 75 ppm., Mg -- 25 ppm., Fe -- 8 ppm., Ca 50 to 200 ppm., Mn -- l ppm., Cu 0.025 ppm., Zn -- 0.2 ppm., B -- 0.025 ppm., Mo -- 0.001 ppm, and S -- 10 ppm. AU82-98 0
FERTILIZERS: Established Facts Orchids respond to added nutrients; slow growers get indigestion from too much; feed is best when they are growing. AU85(1)-37 0
FERTILIZERS: Fertilizers Higher rate produces fewer flowers = for cattleyas a 1 tpg weekly produces only 1 flower on many vigorous plants; a change to 1 tpg. monthly should improve flowering. A84-699 0
FERTILIZERS: For Cattleyas In nutrient culture, growth of hybrid plants was optimal with 50 ppm. each of nitrogen, potassium and magnesium. RHIn parts per million: N-50, P-20, K-50, plus Mg-50. AU82-98 0
FERTILIZERS: For Cattleyas, Paphiopedilums and Miltonias Using organic fertilizer such as fish emulsion (5-1-1) once in a while is good but continued use does not provide enough potassium and phosphorous; a 3-1-1 ratio soluble fertilizer provides them in adequate amounts. A79-1112 0
FERTILIZERS: For Community Pots with Milled Sphagnum Use regular fertilizer at one-third strength, and then increase to one-half. A79-584 0
FERTILIZERS: For Cymbidiums In a nutrient solution growth of hybrid plants was optimal with lOO ppm. nitrogen, 50 to lOO ppm. potassium and 25 ppm. of magnesium. OA79-127 0
FERTILIZERS: For Flowering In Dendrobium nobile and its hybrids flowering is prolific if they are fed every three or four weeks while in active growth with low nitrogen and high phosphorous; from August to October feed 1/2 tpg. with potassium dihydrogen phosphate (KH2P04) NH78(1)10 0
FERTILIZERS: For Heavy Feeders Cymbidiums, lycastes, softcane dendrobiums, zygopetalums are among the heavy feeders and require more fertilizer. AU84-203 0
FERTILIZERS: For Low, Average or Good Light Conditions Peters' fertilizer bags have a table showing that in low light 1/4 tpg is recommended for growth; in medium light 1/2 tpg., and in good light 1 tpg. which is of seasonal importance. Peters. 0
FERTILIZERS: Formulas and Their Meanings The purchased product marked 30-10-10 is a 3-to-one-to-one ratio of nitrogen to phosphorus to potassium. A86-815 0
FERTILIZERS: Formulas, Their Meaning A 12-4-8 formula contains four times as much nutrients, in the same proportions, as a 3-1-2. A61-981 0
FERTILIZERS: For Phalaenopsis In nutrient culture, growth of hybrid plants was optimal with lOO ppm. of nitrogen, 50 to lOO ppm. of potassium and 25 ppm. of magnesium. OA79-127 0
FERTILIZERS: For Plants in Osmunda It needs little if any fertilizer; 1 teaspoon 20-10-10 or 30-10-10- in two gals. water is sufficient at monthly intervals. A67-517 0
FERTILIZERS: For Repotted Plants To stimulate root growth in fir bark mixes keep the same regular schedule with 20-10-10 or 30-10-10 but make it more diluted. A74-433 0
FERTILIZERS: Granular Ones Liquify in Container They can still be used; to avoid the condition arising store it in a dry place in a tightly capped container. A82-487 0
FERTILIZERS: "hardeners" For vandas in the fall a 7-56-14 fertilizer is used to harden off the plant. F68-14 0
FERTILIZERS: High-analysis Types A 9-3-6 fertilizer contains only one-third the value contained in a 27-9-18 formulation; both have the same ratio and cost about the same. OD67-220 0
FERTILIZERS: Ideal Fertility Frequency Use low concentration of dissolved fertilizer at every watering; avoid excess deficiency conditions. PD67-219 0
FERTILIZERS: Injury Caused by A frequent problem; only 2% of the composition of the plant tissue includes mineral content; over-fertilization inhibits growth; diluted liquid fertilizers are best; nature of damage caused and described; refer to A67-474+; AH49+ 0
FERTILIZERS: Inorganic, Made From Chemicals Can be compounded to exact specifications; makes them flexible and adaptable to special conditions and trace elements can be added as required. A70-140 0
FERTILIZERS: In Parts Per Million Six hundred parts of fertilizer to one million parts water passing through a cymbidium is the maximum. AU79-37 0
FERTILIZERS: In Tropical Forests Sources include birds (very little), bats (their presence encourages growth but just why is not explained), monkeys (destructive of plants), ants (an effective part but on a very localised scale), litter-(minor, but physically helpful), rainfall (none), throughfall of rain (much, through leachates), stemflow of rain (significant), dust (some minerals), epiphylls or leaf microflora (significant); for a fascinating essay refer to AU85(3)-13 0
FERTILIZERS: Liquid, for Cattleyas in Fir Bark Rutgers University's urea-form formulation: 1st. application is finely powdered ureaform three heaping tablespoons of ureaform with 20-20-20 two level teaspoons together to five gallons water; subsequent monthly applications of ureaform, 2 rounded teaspoons plus 20-20-20, two level teaspoons per five gallons water applied monthly. A59-508 0
FERTILIZERS: Liquid, for Cymbidiums Rutgers University1s formulation applied one, three or four weeks according to season: per 100 gallons water add 12 oz. of 20-10-10 plus six ounces of 20-20-20, plus four ounces of ammonium nitrate. A59-509 0
FERTILIZERS: Liquid,general Rutgers University1s formulation is 20-20-20, 1 teaspoon plus ammonium nitrate 2 tablespoons together to five gals. water for every other watering. A59-508 0
FERTILIZERS: Liquid Versus Slow-release A liquid programme is preferable because 1. the feed can be accurately measured, 2. the feed can be applied with the watering, 3. liquid feeds are much less expensive. AU84-202 0
FERTILIZERS: Mixed Fresh Each Time Inorganic fertilizers keep well if light is excluded so algae does not grow in it. A67-901 0
FERTILIZERS: Mixed with Pesticides Mixture of Benlate, Cygon and fertilizer is not recommended; don't do it. A73-503 0
FERTILIZERS: Mixing 20-20-20 with Ammonium Nitrate to Get 30-10-10 Mix one ounce of 20-20-20 plus one and one-tenth ounces of ammonium nitrate to get 30-10-10; apply at 1/2 tpg. A75-35 0
FERTILIZERS: Mix of Bone Meal, Superphosphate, Cottonseed Meal, Blood Meal, Guano and Potash for Top Dressing It can be used but it has no advantage over others but lots of risk especially from the potash and blood meal. RMH 0
FERTILIZERS: Mix Your Own 3 oz. of potassium nitrate (saltpetre; sodium nitrate) and two oz. ammonium phosphate dissolved in three gals. water; one ounce to one gal. water for application to plants. OR77-30330-10-10 type, actually 24-8-8, can be made up with 10 lbs. ammonium phosphate 16-20-0; 10 lbs. urea 45-0-0; 4 lbs. potassium sulphate 0-0-50, at a cost of about 40 cents a pound; soluble. OD80-6530-10-10 type, actually, 21-7-7, can be made up with 20 lbs. lawn fertilizer 25-4-5, 6 lbs. ammonium phosphate 16- 12-0; 2 lbs. potassium sulphate 0-0-5-, at a cost of about 30 cents a pound; clay settling out can be discarded. OD80-65; this mix is questionable because indeed a good quantity will settle out; the materials are only sparingly soluble. OWD30-10-10; 3 lbs. urea, 10 oz. triple-super phos- phate, 5 oz. muriate of potash; use 3 heaping teaspoons to five gals, water; the phosphate will not dissolve completely. A68-331A ratio of 4-2-1 can be made from ammonium nit- rate, diammonium phosphate and muriate o... 0
FERTILIZERS: Mode of Application Liquid application is most efficient and effective; should be composed of completely water-soluble elements. OD67-220 0
FERTILIZERS: Organic, Made From Living Organisms Animal manures, fish emul- sion, seaweed emulsion; bone meal, cottonseed meal, etc.; strengths vary and most require dilution; believed to contain natural salts and hormones which cannot be synthesized in chemical foods. A70-140 0
FERTILIZERS: Organic or Inorganic Bacterial activity is low at 50 deg.F. (10 deg.C.) so it is better to use inorganic types of fertilizer in cold weather;use an organic in warmer temperatures. AU73-185Both can be used; liquid organics in gen- eral are relatively expensive but are no more effective than the inorganics. A63-214Commercial manures tend to be alkaline, so the local water supply must be considered in connection; nitrogen in fish fertilizer must rise above 62dF to be released to the plant. A86-586The recommended ratio should be two inorganic feeds to one organic. AU85(l)-37 0
FERTILIZERS: Organic Types Made of relatively insoluble materials as bone meal, dried blood, hoof meal, rock phosphate, etc.; must undergo decomposition before nutrients can be released; the materials slowly decompose; apply twice or thrice yearly. P68(3)9 0
FERTILIZERS: Overhead Sprinkling of Soluble Type It is feasible to do so especially for a large commercial range, but application may be irregular and wasteful. F81-65 0
FERTILIZERS: Proof of Absorption by Cattleya Roots They can absorb nutrients both through the roots and the leaves, as shown in a report published in 1967, and recent reports from Southeast Asia. A83-266 0
FERTILIZERS: Proper Frequency and Strength In plants fertilizer-nutrient is only about 1% of the green weight; water temperature, light, humidity and air are far more important; recommendation: fertil- ize not more than fortnightly, with 1 tpg. of 30-10-10 and flush with water between. A69-55 0
FERTILIZERS: Proportions One teaspoon per gallon is equivalent to one pound per 100 gallons of water. OD71-95 0
FERTILIZERS: Seasonal Changes If plants are in a bark mix, prosper from a 30-10-10 mix all year round; for those at rest, do not water or fertilize. A81-1223It is a fallacy to change fertilizers according to season; it is a belief based more on folk-lore than on proven fact. SA-85-168 0
FERTILIZERS: Should Vary with the Medium Used For osmunda; tree fern, terrestrials, Holite, Solite, etc., use 10-5-8 at 1 gram per liter of water; for bark use 30-4-8 at 1.15 grams per liter. Hort. reviews 5,358 0
FERTILIZERS: Slow Release Fertilizers Include Golden Vigoro, Mag-Amp, Nitrophoska (Aus.), Osmocote, QUE Slow Release, etc. RMH 0
FERTILIZERS: Survey of Contents Nutrient element content of commercial fertilizers such as Peters, Plantprod, etc., plus their trace elements for 13 differ- ent chemicals listed; refer to OA87-201 0
FERTILIZERS: Tailored Feeding Plan 1st week: fish emulsion; 2nd week: for vegetative growth 30-10-10 but plants making roots or flowers get 7-28-15 and resting plants get only water; 3rd week: all plants 18-18-18 except C.mossiae types waiting to bloom which get 6-7-21 as tonic, then one month before flowering they get high phosphorous again; 4th week: same as second week. A70-140+ 0
FERTILIZERS: Top Dressing In late spring top-dress the pots with a physical blend of Milorganite or other processed sewage, plus dried blood in a 2 to 1 ratio. OA80-81 0
FERTILIZERS: Top Dressing Using a 6-6-6 Formulation Is not recommended because the extra potash might cause injury. A79-370 0
FERTILIZERS: To Promote Better Flowers A wide-spread error is that high-phosphorous fertilizers promote more blooms; however, a deficiency of phosphorous does inhibit blooming; a soluble 15-30-15 fertilizer at 1 tpg. about once every two weeks will supply the relatively small amount needed. A75-1090 0
FERTILIZERS: Toxic Effects Plants cannot limit the intake of the following elements so they become toxic if overdone: nitrogen, potassium, magnesium, iron, zinc, boron. SA85Dec-168 0
FERTILIZERS: With Micronutrients They are of questionable real value; it is probably false advertising to claim otherwise. OD67-221 0

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