Soil Amendment List
Alfalfa Meal (3-1-2)
Easily accessible source of nitrogen; creates larger flowers; increases cold tolerance; great fertilizer for mixing into the existing soil around roses (not too close to the stem/main root ball) in the spring.
Aluminum Sulfate
Creates acidic soil for azaleas, gardenias, etc. Changes hydrangeas color to blue or pink depending on pH.
Ammonium Sulfate (21-0-0)
High nitrogen for dark green color and rapid growth. Sulfur helps to acidify the soil and promote stronger plant growth. A great fertilizer to help establish new mango trees.
Blood Meal (12-0-0)
High in nitrogen and water soluble; good to use in beds that are replanted year after year to replenish lost nutrients. It can also be used to slightly acidify soil and is one of the fastest acting fertilizers to correct a nitrogen deficiency. Great for fertilizing cool season annuals. Effective deer and rabbit repellent.
Bone Meal (3-12-0)
Adds phosphorus to soils that have a pH below 7; creates a well balanced fertilizer when paired with manure-based composts. Commonly used when planting spring bulbs and amending vegetable beds for tomatoes, peppers, cucumbers, and melons. Adds calcium to soil over time to prevent blossom end rot when applied at a rate of 10 lbs per 100 sq. ft.
Corn Meal
Can be used to organically treat lawn brown patch at a rate of 20 lbs per 1000 sq. ft. Excellent compost starter at a rate of 1 lb per cubic yard of compost. Can also be applied to fire ant mounds as an organic ant killer.
Corn Gluten Meal (9-0-0)
This is the protein portion of corn meal. If applied prior to weed seed germination, it acts as an organic pre-emergent (the active ingredient in Preen). Can also be used as an all-natural weed-n-feed at the rate of 20 lbs per 1000 sq. ft.
Cottonseed Meal (7-3-2)
Excellent all-purpose slow release winterizer fertilizer to feed plants from fall until spring. Aerates dense soil and helps with moisture retention in sandy soil. Unlikely to burn sensitive plants and is great for strawberries as well as acid loving plants. Can be added to turf fertilizer to encourage better root development at a rate of 3 lbs per 100 sq. ft.
Gypsum
Excellent source of calcium and can be mixed into existing soil for a once-a-season treatment. Breaks down quickly when watered into the soil; prevents blossom end rot in tomato and pepper plants. Can help to repair salt damage and dog urine spots in the lawn. Breaks up clay soil when applied at a rate of 6 lbs per 30 sq. ft.
Horticultural Molasses
Provides a natural food source for microbial populations within the soil and can improve compost piles and aide in faster break down of nutrients. Has been shown to deter fire ants at a rate of 20 lbs (granular) per 1000 sq. ft. Also used as an organic nutsedge killer at a rate of 20 lbs per 1000 sq. ft. (granular) or 1/2 cup per gallon of water (liquid) - may require several treatments.
Iron (11-0-0)
Corrects yellowing in plants and turf. If it also contains sulfur it makes a good acidifier for plants that prefer a lower pH and will not burn if applied according to directions. Available as a liquid and a granule.
Kelp Meal (1-0-2)
Gentle non-burning fertilizer for vegetable transplants. Is said to enhance avocado production and flavor if trees are fertilized with it in January–February.
Limestone
Good source of calcium and used to raise soil pH. Finely ground limestone = Aglime. If dolomite is added to it then it is called dolomitic lime. Dolomitic lime is a good source for magnesium, but can also be substituted with epsom salt or worm castings. If Aglime or dolomitic lime are heated until burnt and then have water added to them they become hydrated lime, which is more concentrated and caustic, and is used to create an insect repellent barrier around your home's foundation.
Liquid Humus
Helps plants to grow stronger roots, increases nutrient uptake ability, and helps plants produce more flowers, fruit, and foliage.
Magnesium Sulfate (Epsom Salt)
Prevents yellowing of plants due to a magnesium deficiency. Helps encourage brighter white blooms on hydrangeas.
Muriate of Potash (0-0-60)
Also called potassium chloride; the most common source of potassium (K) in agriculture. It can increase the disease resistance in plants and is used to help overcome potassium deficiencies. Helps potatoes develop roots faster when applied to planting rows at a rate of 1/2 lb per 100 ft of row crop.
Rock Phosphate
Used to correct nutrient deficiency in phosphorus/phosphate; organic; helps promote blooming.
Sulfur
Fungicidal properties that control black spot, powdery mildew, rust, and canker on roses. Controls thrips, mites, and chiggers in turf grass. Prevents cut potatoes from rotting if dusted with sulfur and allowed to dry slightly before planting. Slightly acidifies soil.
Zinc Sulfate
Provides a source of zinc to promote good nut production and prevents Rosette on pecan trees.