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  • How Much Bat Guano (8-1-1) Should I Use?

    Created by Omar Lopez on

    I recently purchased the Mexican Bat Guano organic fertilizer (8-1-1) and was wondering: What would the recommended dosage be for citrus seedlings (under 2 months old)? Also, the directions on the container mention mixing 1-3 tbsp. per gallon. Is there a more accurate measurement where I could be more sure that I am applying that 8-1-1 ratio when I water the plants?

    Thank you

  • Author
  • #205703

    Eric Vinje

    Hello Omar –

    To figure out how to get a more precise ratio of fertilizer per gallon of water you can start with the concept that your 8-1-1 fertilizer contains 8% Nitrogen, 1% Phosphorus and 1% Potassium. I am looking at a one pound container of Mexican Bat Guano, so that means that 8% of it is Nitrogen. Now in order to figure out how much Nitrogen is in one Tablespoon of guano, you need to know how many Tablespoons are in the one pound container. Weighing out one Tablespoon of the guano will tell you that it weighs 0.015 lbs therefore 1 lb divided by 0.015 lbs gives you about 66.67 Tablespoons per pound of fertilizer.

    ? %N
    1 Tbs
    = 66.67 Tbs
    1 lb
    x 1 lb fert
    8 %N
    = 8.33 %N
    1 Tbs

    So what percentage of Nitrogen is in 1 Tablespoon of fertilizer? If you multiply 66.67 Tablespoons per 1 pound by 1 pound of fertilizer per 8% of Nitrogen you get 8.33% Nitrogen per Tablespoon of fertilizer.

    In order to fertilize at or close to the exact 8-1-1 ratio mix just under 1 Tablespoon of guano with 1 gallon of water. This should be a good ratio for your citrus seedlings. Be sure to pour no more than a shot glass’ worth of the fertilizer around and slightly away from the circumference of the tree trunks. It is also important that you fertilize the seedlings NO MORE than two times per year – once in early spring and again in late summer is generally best. You can utilize the left over fertilizer mixture on other house plants, garden vegetables or lawns as it is great for promoting plenty of vegetative growth.

    Best of luck!

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