The Hoagland solution is a hydroponic nutrient solution that was developed by Hoagland and Arnon in 1938 and revised by Arnon in 1950 and is one of the most popular solution compositions for growing plants (in the scientific world at least). The Hoagland solution provides every nutrient necessary for plant growth and is appropriate for the growth of a large variety of plant species. The solution described by Hoagland and Arnon in 1950 has been modified several times, mainly to add iron chelates, the original concentrations for each element are shown below.
- N 210 ppm
- K 235 ppm
- Ca 200 ppm
- P 31 ppm
- S 64 ppm
- Mg 48 ppm
- B 0.5 ppm
- Fe 1 to 5 ppm
- Mn 0.5 ppm
- Zn 0.05 ppm
- Cu 0.02 ppm
- Mo 0.01 ppm
The Hoagland solution has a lot of N and K so it is very well suited for the development of large plants like tomato and bell pepper. The solution is very good for the growth of plants with lower nutrient demands as well, such as lettuce and aquatic plants with the further dilution of the preparation to 1/4 or 1/5 of the original.
- Potassium nitrate(KNO3)
- Magnesium sulphate heptahydrate, MgSO4•7H2O, and potassium dihydrogen phosphate (Potassium phosphate monobasic), KH2PO4
- Iron EDTA or Iron chelate, Fe-EDTA
- Boric Acid, H3BO3
- Copper Sulfate, CuSO4
- Zinc sulfate heptahydrate, ZnSO4•7H2O
- Manganese chloride, MnCl2•4H2O
- Sodium molybdate, Na2MoO4•2H2O,
- Calcium nitrate, Ca(NO3)2•4H2O. Last solution must be added as final.
|Component||Stock Solution||mL Stock Solution/1L|
|2M KNO3||202 g/L||2.5|
|1M Ca(NO3)2•4H2O||236 g/0.5L||2.5|
|Iron (Sprint 138 iron chelate)||15 g/L||1.5|
|2M MgSO4•7H2O||493 g/L||1|
|1M NH4NO3||80 g/L||1|
|H3MoO4•H2O or||0.09 g/L||1|
|1M KH2PO4 (pH to 6.0)||136 g/L||0.5|
- Make up stock solutions and store in separate bottles with appropriate label.
- Add each component to 800 mL deionized water then fill to 1 L.
- After the solution is mixed, it is ready to water plants.
What many persons may not know is that the Hoagland/Arnon nutrient solution formulations have a use intent that one gallon of nutrient solution is used per plant with replacement on a weekly basis. If any of these use parameters are changed, i.e., the volume of solution, number of plants, and/or frequency of replacement, plant performance will be significantly affected, this is a factor that may not be realized by persons using the formulations.
- Hoagland, Dennis (1938). The water-culture method for growing plants without soil (Circular (California Agricultural Experiment Station), 347. ed.). Berkeley, Calif. : University of California, College of Agriculture, Agricultural Experiment Station. Retrieved 1 October 2014.
- Hoagland and Arnon (1950). The water-culture method for growing plants without soil. Berkeley, Calif. : University of California, College of Agriculture, Agricultural Experiment Station.
- "The Hoaglands Solution for Hydroponic Cultivation". Science in Hydroponics. Retrieved 1 October 2014.
- "Hydroponics 101 - Nutrient Solutions: Historical Background, Formulations and Use, Part 1". Garden Greehouse. Retrieved 1 October 2014.
- The exact composition of the Hoagland solution
- Description of the solution
- National Academy of Sciences: A Biographical Memoir of Dennis Robert Hoagland by Walter P. Kelley