Anything that is added to soil to improve its pH, texture, structure, fertility, drainage, or other qualities, is considered a soil amendment. Through the use of soil amendments, almost any soil or piece of land can be made fertile. The soil amendments you will select depends entirely on how the soil needs to be changed.

One of the first things to consider is the pH of the soil. If your soil is too acidic (low pH) or too alkaline (high pH), plants will not be able to properly take up the nutrients that are present. Adding fertilizers or other amendments to soil with an extreme pH will not help – you have to address the pH issue first.

Alfalfa Meal Acts quickly because it decomposes fast. Excellent for roses because it contains magnesium which your roses love. Alfalfa Meal also contains a natural fatty acid growth stimulant called triacontanol which helps boost growth of all types of plants.

is a natural mineral product that has been mined in Utah for over 70 years. Containing a broad spectrum of over 70 metabolically active minerals and trace elements (including calcium, sulfur, boron, molybdenum, zinc and copper), Azomite requires no mixing, it’s odorless, it won’t burn plants, and it won’t restrict aeration or water penetration. 

Blood meal
is a very rich non-synthetic source of nitrogen, which is a crucial component of plant cells and one of the basic components of chlorophyll, the substance that helps plants convert sunlight into sugars. It helps plants grow healthy root systems and produce green foliage more rapidly, making them more resistant to pests and diseases. Blood meal also helps repel deer.

Bone meal
is rich in phosphorous, a mineral that plants need for healthy root development and flower growth. It also contains calcium and a little bit of nitrogen, both of which are beneficial to plants. Bone meal is taken up by plants slowly over time, so as long as it is used sparingly, there is little risk of 'burning' plants with too much of this fertilizer.

Coco coir can replace peat moss in potting soil and seed starting medium. The compressed bricks are easy to handle and store and take up much less space than peat moss. Coconut coir is disease resistant and has excellent air space and water holding capacity (8-10 times its volume) in potting soil. Coir is pH neutral, so there is no need to add lime to increase the pH in potting soils as is needed when using peat moss.

 is rich in organic nutrients and beneficial organisms that speed nutrient uptake. Garden compost can be full of harmful pests and diseases and is best used in outdoor gardens.

Cow Manure Compost
 contains many beneficial bacterial, helps to break-up soils that are high in clay content and adds moisture holding capacity to sandy soils.

Crab shells
are a potent, organic source of nitrogen, phosphorus, calcium and magnesium, and are also an excellent source of chitin. Crab shells also help inhibit blossom end rot.

Earthworm castings
are a very concentrated fertilizer and soil amendment, they will never burn your plants. Worm castings provide all the micro-nutrients necessary for plant growth 

Feather Meal
 is very high in nitrogen and is excellent for plants requiring a consistent supply of nitrogen.

Glacial Rock Dust
includes a wide variety of rocks containing a spectrum of trace materials that are collected and pulverized by the expansion/contraction of the glaciers. Glacial rock dust helps neutralize acidity (though not as effectively as lime) improves soil structure, moisture-retaining ability, helps bacterial activity and replaces key soil elements, reversing soil depletion. An excellent source of readily available calcium, iron, magnesium, and potassium plus trace elements and micronutrients. Glacial rock dust also Increases phosphorus availability.

is a silicate mineral containing iron, potassium, and as many as thirty other elements. It has the unique ability to loosen hard soils as well as bind sandy soils. Greensand is a naturally occurring seashore deposit that regulates the release of nutrients in soil and assists in moisture retention

are 100% recycled, highly porous, chemical and toxin-free hydroponic growth mediums and soil aerators engineered to deliver superior air and water retention ratios Growstones provide over 70% more aeration than perlite.

Guano (bat and seabird)
 are some of the best organic fertilizers in the world today. Mix it into your potting soil when potting new plants or repotting old ones. Top-dress potted plants, apply it to your lawn, flower and vegetable gardens. Guano greatly enhances aromas and flavors.

is a good source of sulfur, loosens heavy clay soils, minimizes salt damage to plants. Gypsum also helps promote root growth.

 (commonly known as Hydroton) is used to expedite drainage and retain air within the growing medium. Hydroclay is a popular soil amendment in container gardens.

Humus consists of decayed organic matter used as a soil amendment to add fertility, hold moisture and provide aeration. Humus is also widely used in making compost tea.

is a great source of potassium, as well as a broad spectrum of micronutrients such as iron, manganese, boron, molybdenum, zinc and copper. It also contains growth-stimulating hormones that lead to vigorous growth and good resistance to pests and disease. Kelp can be used throughout the year as a liquid or foliar fertilizer.

is a pulverized rock powder made from chalk or limestone that is high in calcium and magnesium. Dolomite lime comes from a different source and is also high in magnesium. Both of the elements have the effect of raising the pH (lowering the acidity) of soil.

is an excellent source of nitrogen and other nutrients (such as calcium and iron), but it is essential to let it rot completely before adding it to your garden. Fresh animal manure can contain as much nitrogen as chemical fertilizers, and can burn plants or stunt growth. Our bagged manures are pre-rotted and ready for use.

increase the surface-absorbing area of roots 100-1,000 times, thereby greatly improving the ability of the plant to access soil resources.  Several miles of fungal filaments can be present in a thimble of soil. Mycorrhizal fungi also release powerful enzymes into the soil that dissolve hard-to-capture nutrients, such as organic nitrogen, phosphorus, iron and other "tightly bound" soil nutrients. Mycorrhizae are widely used during transplanting and help reduce transplant shock. For more information on Mycorrhizal Fungi, click here.

Neem Seed Meal
 is an excellent all-natural fertilizer for enriching garden and agricultural soils encouraging optimal plant development.

is used as a soil amendment or alone as a medium for hydroponics or for starting cuttings. When used as an amendment, perlite has high permeability/low water retention and helps prevent soil compaction.

Rock phosphate
is a naturally mined mineral that supplies phosphorus and calcium and stimulates root growth. Rock phosphate also helps plants use water more efficiently.

Silica strengthens interior and exterior cell walls keeping leaves and stems upright. This allows for greater opportunity for photosynthesis. Silica also prevents fungal infections and insect infestations and increases tolerance to heat and other environmental stresses.

Sphagnum peat moss
 is completely organic, odorless and natural. Peat moss absorbs water up to 20 times its dry weight; the absorbed water is then slowly released to plant roots. Sphagnum peat moss aerates and lightens heavier soils such as clay. Sphagnum contains no nutrients of its own, and the pH ranges from 3-5. After decomposing for several months, the pH could continue to drop and become very acidic.

can be highly effective as a pathogen control agent. Trichoderma also encourage vigorous growth.

, when mixed with hard or sticky soil, creates air channels and allows the soil mix to breathe, providing the necessary air to maintain vigorous plant growth. Vermiculite is also used to germinate seeds, store bulbs and as a mushroom growing substrate.

Want to learn more? Check out the other topics in the GYOstuff Learning Center.

The GYOstuff email newsletter. Sign up today with just your name & email address.

Name: *
Email: *