Natural & Organic: Fertilizers & Amendments
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Alfalfa, Meal or Pellets: 2-1-2 (approx.)
Simply ground-up alfalfa hay, either loose or pressed into pellet form. We recommend the pellets, as
they're much easier and less messy to work with, and they quickly break down into meal when
moistened. Alfalfa supplies all three major plant nutrients, plus sugars, starches, and vitamins that
nourish soil microbes, and tricontanol, a plant growth hormone.
Simply ground-up alfalfa hay, either loose or pressed into pellet form. We recommend the pellets, as
they're much easier and less messy to work with, and they quickly break down into meal when
moistened. Alfalfa supplies all three major plant nutrients, plus sugars, starches, and vitamins that
nourish soil microbes, and tricontanol, a plant growth hormone.
Blood Meal: 12-0-0
A by-product of the meat industry, blood meal is an excellent source of readily available nitrogen. It also
may help repel deer and rabbits.
A by-product of the meat industry, blood meal is an excellent source of readily available nitrogen. It also
may help repel deer and rabbits.
Bone Meal: 0-10-0
Another by-product of meat production, bone meal is high in phosphorous and also contains calcium.
Bone meal releases its nutrients faster than rock phosphate, which also provides phosphorous. It's
often used to fertilize bulbs, because they require high levels of this nutrient.
Another by-product of meat production, bone meal is high in phosphorous and also contains calcium.
Bone meal releases its nutrients faster than rock phosphate, which also provides phosphorous. It's
often used to fertilize bulbs, because they require high levels of this nutrient.
Compost: 1-1-1 (approx., can vary widely)
As organic gardeners know, compost is about the single most beneficial thing you can add to your
garden soil. Its nutrient content varies widely, depending on what materials went into the compost pile,
but its usefulness goes far beyond an N-P-K value. Compost adds bulk organic matter to the soil. Most
importantly, it infuses the soil with beneficial microbes.
As organic gardeners know, compost is about the single most beneficial thing you can add to your
garden soil. Its nutrient content varies widely, depending on what materials went into the compost pile,
but its usefulness goes far beyond an N-P-K value. Compost adds bulk organic matter to the soil. Most
importantly, it infuses the soil with beneficial microbes.
Diatomaceous Earth
Made of the fossilized exoskeletons of microscopic plankton, diatomaceous earth is an effective way to
control slugs and crawling insects. It looks and feels like powder to us, but to insects, it's jagged and
sharp as broken glass. It works by piercing the skin or exoskeleton of pests, causing them to die of
dehydration.
Made of the fossilized exoskeletons of microscopic plankton, diatomaceous earth is an effective way to
control slugs and crawling insects. It looks and feels like powder to us, but to insects, it's jagged and
sharp as broken glass. It works by piercing the skin or exoskeleton of pests, causing them to die of
dehydration.
Epsom Salts (Magnesium Sulfate)
Epsom salts provide magnesium, which is essential for the production of chlorophyll.
Epsom salts provide magnesium, which is essential for the production of chlorophyll.
Cottonseed Meal: 5-2-1 (approx.)
Cottonseed meal supplies all three major nutrients. Its very acidic pH make it a good choice for fertilizing
acid-loving plants such as potatoes, blueberries, and rhodies.
Cottonseed meal supplies all three major nutrients. Its very acidic pH make it a good choice for fertilizing
acid-loving plants such as potatoes, blueberries, and rhodies.
Rock Phosphate: 0-3-0
A slow-release phosphorous source, rock phosphate is actually 30% phosphorous, with about 3%
readily available.
A slow-release phosphorous source, rock phosphate is actually 30% phosphorous, with about 3%
readily available.
Gypsum (Calcium Sulfate)
Besides supplying the nutrients calcium and sulfur, gypsum is used primarily for loosening compacted
soils.
Besides supplying the nutrients calcium and sulfur, gypsum is used primarily for loosening compacted
soils.
Sulfur
Sulfur is the first fungicide used in agriculture, and it's still being used today, because it's safe and
effective. Sulfur dust can be applied dry by hand or with a puffer, or mixed with water and applied with a
sprayer. Sulfur is also used to lower the pH of soil for acid-loving plants.
Sulfur is the first fungicide used in agriculture, and it's still being used today, because it's safe and
effective. Sulfur dust can be applied dry by hand or with a puffer, or mixed with water and applied with a
sprayer. Sulfur is also used to lower the pH of soil for acid-loving plants.
Neem Oil
Extracted from the East Indian neem tree, neem oil is both an insecticide and fungicide. It doesn't kill
insects directly, but instead makes them stop feeding. It also interferes with their molting process, which
eventually will cause them to be crushed to death by outgrowing their own exoskeletons, and with their
reproductive processes, preventing them from multiplying. Neem works on the plant's surface, and is
also taken up into its system, where it will affect insects that suck the plant's juices. Neem is non-toxic to
people and pets (it's found in some toothpastes!) and harmless to beneficial insects.
Extracted from the East Indian neem tree, neem oil is both an insecticide and fungicide. It doesn't kill
insects directly, but instead makes them stop feeding. It also interferes with their molting process, which
eventually will cause them to be crushed to death by outgrowing their own exoskeletons, and with their
reproductive processes, preventing them from multiplying. Neem works on the plant's surface, and is
also taken up into its system, where it will affect insects that suck the plant's juices. Neem is non-toxic to
people and pets (it's found in some toothpastes!) and harmless to beneficial insects.
Insecticidal Soap
Insecticidal soaps work by dissolving the protective body coating of soft-bodied insects such as aphids
and scale insects, and disrupting the passage of air and water through the membranes of their bodies.
Insecticidal soaps work by dissolving the protective body coating of soft-bodied insects such as aphids
and scale insects, and disrupting the passage of air and water through the membranes of their bodies.
Greensand: 0-0-3
Greensand comes from ancient seabed deposits. It contains 3% available potassium and all the
essential trace elements. It also has a tremendous moisture-retaining capacity, which makes it very
useful for container gardens.
Greensand comes from ancient seabed deposits. It contains 3% available potassium and all the
essential trace elements. It also has a tremendous moisture-retaining capacity, which makes it very
useful for container gardens.
Corn Gluten Meal: 9-0-0
Besides being a very good source of available nitrogen, corn gluten has become widely known for its
weed control ability. Corn gluten meal acts as a pre-emergent herbicide - it prevents seeds from
germinating, but won't harm established plants. Because of this, it shouldn't be used anywhere you plan
to plant new seeds in the next several months. Probably its most common use is as a fertilizer/weed
preventer on lawns.
Besides being a very good source of available nitrogen, corn gluten has become widely known for its
weed control ability. Corn gluten meal acts as a pre-emergent herbicide - it prevents seeds from
germinating, but won't harm established plants. Because of this, it shouldn't be used anywhere you plan
to plant new seeds in the next several months. Probably its most common use is as a fertilizer/weed
preventer on lawns.
Fish Meal: 9-4-1 (approx.)
A great source of nitrogen, phosphorous, and trace elements. Fish meal also makes an excellent
compost activator. Its main drawback is its pungent odor.
A great source of nitrogen, phosphorous, and trace elements. Fish meal also makes an excellent
compost activator. Its main drawback is its pungent odor.
Kelp Meal: 1-0.1-2
Kelp is a source of potassium, as well as all the trace minerals found in the sea. It contains lots of
carbohydrates and amino acids that nourish soil microbes. Kelp is one of the fastest growing plants in
the world, and the organic compounds such as cytokinins, auxins, and gibberellins found in kelp also
stimulate cell growth and division in garden plants. Used as a fertilizer, kelp enhances seed
germination, improves nutrient uptake, cold resistance, and stress recovery, and aids in the formation of
humus in the soil. It's also a great compost activator.
Kelp is a source of potassium, as well as all the trace minerals found in the sea. It contains lots of
carbohydrates and amino acids that nourish soil microbes. Kelp is one of the fastest growing plants in
the world, and the organic compounds such as cytokinins, auxins, and gibberellins found in kelp also
stimulate cell growth and division in garden plants. Used as a fertilizer, kelp enhances seed
germination, improves nutrient uptake, cold resistance, and stress recovery, and aids in the formation of
humus in the soil. It's also a great compost activator.
| N P K |
| N |
| P Ca |
| N P K |
| N |
| N P K pH- |
| Mg S |
| N P K Trace |
| K Trace |
| K Trace |
| P |
| pH- |
| Ca S |
| N - Nitrogen P - Phosphorous K - Potassium Ca - Calcium Mg - Magnesium S - Sulfur Trace - Trace nutrients pH+ - Raise soil pH pH- - Lower soil pH Growth Stimulant Herbicide Insecticide Fungicide Soil microbes |
Lime
There are two main types of lime, calcitic (limestone) and dolomite. Lime is used mainly to neutralize soil
acidity. Both types contain calcium, and dolomite lime is also a source of magnesium.
There are two main types of lime, calcitic (limestone) and dolomite. Lime is used mainly to neutralize soil
acidity. Both types contain calcium, and dolomite lime is also a source of magnesium.
| pH+ Ca Mg |
| Symbol Key |
Here's a list of some common organic fertilizers, soil amendments, and pest control materials. It's by no means
complete, but these are the ones you'll find most commonly, alone or in commercial organic fertilizer mixes.
complete, but these are the ones you'll find most commonly, alone or in commercial organic fertilizer mixes.