HGRH Fertilizer Formulation

The following information can be cut/pasted into a publications with very little modification. The units such as "mg/L" will need to be rewritten to scientific notation, but this webpage does not support superscript text. Also, your text may need to address how often plants were fertilized. The formulation changed in 2009-2010, but remained nearly identical in N-P-K and pH. Please note dates each formulation was used:

1/01/2024 - Present

Plants were irrigated as necessary with acidified water supplemented with water-soluble fertilizer (20N-1.3P-15.8K; ICL Specialty Fertilizers, Dublin, OH) to provide the following (in mg/L): 150 N, 9.8 P, 119 K, 12 Mg, 21 S, 1.5 Fe, 0.4 Mn and Zn, 0.2 Cu and B, and 0.1 Mo. Nitrate and ammoniacal sources of nitrogen were provided as 61% and 39% total N respectively.

1/15/2018 - 12/31/2023

Plants were irrigated as necessary with acidified water supplemented with water-soluble fertilizer (20N-1.3P-15.8K; ICL Specialty Fertilizers, Dublin, OH) to provide the following (in mg/L): 150 N, 9.8 P, 119 K, 12 Mg, 21 S, 1.5 Fe, 0.4 Mn and Zn, 0.2 Cu and B, and 0.1 Mo. Nitrate and ammoniacal sources of nitrogen were provided as 61% and 39% total N respectively. Irrigation water was supplemented with 93% sulfuric acid (Brenntag, Reading PA) at 0.08 mL/L to reduce alkalinity to 100 mg/L and pH to a range of 5.8 to 6.2.

8/20/15 - 1/14/2018

Plants were irrigated as necessary with acidified water supplemented with a combination of two water-soluble fertilizers (3:1 mixture of 15N–2.2P–12.5K and 21N–2.2P–16.6K, respectively; Everris NA, Dublin, OH) to provide the following (in mg/L): 150 N, 20 P, 122 K, 38 Ca, 15 Mg, 0.8 Fe, 0.4 Mn and Zn, 0.2 Cu and B, and 0.1 Mo. Nitrate form was 76% of nitrogen provided. Irrigation water was supplemented with 93% sulfuric acid (Brenntag, Reading PA) at 0.08 mL/L to reduce alkalinity to 100 mg/L and pH to a range of 5.8 to 6.2.

8/1/10 - 8/19/2015

Plants were irrigated as necessary with acidified water supplemented with a combination of two water-soluble fertilizers (3:1 mixture of 15N–2.2P–12.5K and 21N–2.2P–16.6K, respectively; The Scotts Co., Marysville, OH) to provide the following (in mg/L): 200 N, 26 P, 163 K, 50 Ca, 20 Mg, 1.0 Fe, 0.5 Mn and Zn, 0.24 Cu and B, and 0.1 Mo. Nitrate form was 76% of nitrogen provided. Irrigation water was supplemented with 93% sulfuric acid (Brenntag, Reading PA) at 0.08 mL/L to reduce alkalinity to 100 mg/L and pH to a range of 5.8 to 6.2.

10/15/09 – 5/31/10

Plants were irrigated as necessary with acidified water supplemented with water-soluble fertilizer (15N–1.3P–13.3K; Greencare Fertilizers, Kankakee, IL) to provide the following (in mg/L): 200 N, 17 P, 176 K, 40 Ca, 27 Mg, 1.0 Fe, 0.5 Mn and Zn, 0.24 Cu and B, and 0.1 Mo. Irrigation water was supplemented with 93% sulfuric acid (Ulrich Chemical, Indianapolis, IN) at 0.08 mL/L to reduce alkalinity to 100 mg/L and pH to a range of 5.8 to 6.2.

6/1/10 – 7/31/10

Plants were irrigated as necessary with acidified water supplemented with water-soluble fertilizer (21N–2.2P–16.6K; The Scotts Co., Marysville, OH) to provide the following (in mg/L): 200 N, 20 P, 158 K, 1.0 Fe, 0.5 Mn and Zn, 0.24 Cu and B, and 0.1 Mo. Irrigation water was supplemented with 93% sulfuric acid (Ulrich Chemical, Indianapolis, IN) at 0.08 mL/L to reduce alkalinity to 100 mg/L and pH to a range of 5.8 to 6.2.

3/1/98-10/14/09

Plants were fertilized as necessary with acidified water supplemented with 15N–2.2P–12.5K water-soluble fertilizer (Excel Cal-Mag; Scotts, Marysville, OH) to provide the following (in mg/L): 200 N, 29 P, 167 K, 67 Ca, 27 Mg, 1.0 Fe, 0.5 Mn and Zn, 0.24 Cu and B, and 0.1 Mo. Irrigation water was supplemented with 93% sulfuric acid (Ulrich Chemical, Indianapolis) at 0.08 mL/L to reduce alkalinity to 100 mg/L and pH to a range of 5.7 to 6.3.

Irrigation Solution Analyses

Substrat​​e Analyses

Soilless mix Labels

Fertilizer Labels

The following fertilizer is dispensed (See HGRH Fertilizer Formulation above) within greenhouse zones at spigot:

The following slow release fertilizers are available upon request: