You are viewing all Organic Growers Supply products related to “Soil Amendments.”

Amendments and Fertilizers

Amendments and Fertilizers
Custom Mixing
8193 Fedco has a new baby! We adopted a soil mixer from our friends at the Maine Cap N’ Stem Mushroom Co. It’s round and red and adorable, and we are... read more
Amendments and Fertilizers
Soil Testing & Organic Fertilizer Recommendation Service
8194 Don’t guess—test! Applying fertilizers and soil amendments without the guidance of a professional soil test is like driving downtown with your... read more


North Country Organics® Bone Charout-of-stock, COVID complications
8283 (0-16-0, 32% P2O5, approx. 30% Ca) Burned bone meal provides large amounts of readily available phosphorus. The most economical source of P for... read more


20 Mule Team Borax Solubor® DF
8219 (Sodium Tetraborate, 20.5% B) Soluble borate for fluid fertilizers and nutrient sprays. Boron is essential for all stages of tree growth and fruit... read more
Allganic Potassium Sulfate of Potash Water Soluble 0-0-52
8246 (0-0-52) The most economical source of available potassium. Apply at 200–500#/acre or 1#/100 sq ft. read more
8195 (94% CaCO3) When the price of aragonite spiked a few years ago, we tried to steer growers toward the chemically identical Calcitic Limestone, but... read more
Azomite, Coarse
8213 (0-0-0.2, 5% Ca) Named for its A-to-Z of Minerals including Trace Elements; contains over 67 minerals beneficial to plants and animals.

A mix of

... read more
Azomite, Micronized
8216 (0-0-0.2, 5% Ca) Named for its A-to-Z of Minerals including Trace Elements; contains over 67 minerals beneficial to plants and animals, including... read more
BrixBlend Basalt
8222 (49.3% SiO2, 13.3% Al2O3, 9.2% CaO, 5.7% MgO, plus trace minerals) A paramagnetic stone powder from the Pioneer Valley of Massachusetts for... read more
Calphosout-of-stock, clearance
8225 (0-3-0, 20% Total P, 20% Ca, trace minerals) This soft-rock phosphate is an excellent choice for calcium-deficient soils as plants will take up... read more
Granite Meal
8231 Contains about 5% potassium in very slow-release form. Plants need potassium for sugar and starch production. Granite meal can be added to the... read more
Greensandout-of-stock, clearance
8234 (49.3% SiO2, 3.72% Fe) “Greensand has been successfully used for soilbuilding for more than 100 years,” according to Rodale’s Encyclopedia of... read more
Gypsum, pelletized
8204 (Calcium Sulfate CaSO4•2H2O, 23% Ca, 17% S) Gypsum is a good source of calcium when the pH is already at a desired level. The sulfur in gypsum... read more
Hum-Amend Max
8240 Max out your soil health! This is a powerful soil restoration amendment designed to raise your soil’s cation exchange capacity while adding high... read more
K-Mag Granular Trio® SOP-MG
8237 (22%K2O, 10.8% Mg, 22% S) (Sulfate of Potash Magnesium) Langbeinite is a marine deposit of potassium sulfate and magnesium sulfate in soluble... read more
Micronutrients Liquid Mineral
8244 While trace mineral products like Azomite® can be helpful for maintaining background levels of a wide variety of elements, they don’t have the... read more
Monterey Epsom Salts
8228 (9.8% water-soluble Mg, 12.9% S) Magnesium is a building block of chlorophyll and therefore essential to efficient photosynthesis. In... read more
Phosphate, Tennessee Brown Rock
8252 (0-4-0, 23% total P2O5) The consistency of rich soil. Comes from the washing piles left behind when high-grade ore was extracted to produce... read more
Pro Pelleted Calcitic Limestone
8198 Pro-Select Prill (87% CaCO3, 7% MgCO3). Cal Carb Equivalent 95.8%. The most common and most frequently used soil conditioner. Calcitic is the... read more
Pro Pulverized Dolomitic Limestone
8201 (53% CaCO3, 42% MgCO3). Cal Carb Equivalent 102.9%. Use to sweeten soil (raise pH) and provide calcium where excess magnesium is not a problem.... read more
Tiger 90CR Organic Sulfur
8249 90% elemental sulfur, 10% bentonite clay. Use to lower soil pH (make it more acidic). Often helpful for both lowbush and highbush blueberries, and... read more
8207 (48% CaO and 52% SiO2). Cal Carb Equivalent 76.0%. Soluble-grade and at least 95% pure (may contain trace amounts of iron, manganese and... read more
ZeoMax Garden Aid
8255 Zeolites are aluminosilicate lattices, derived from volcanic ash, that hold up to 55% of their weight in water in the small cavities of their... read more
Zinc, Liquidout-of-stock, Clearance
8327 (10% Zn, 5% S) Plants deficient in zinc show delayed maturity and stunted new growth. Zinc doesn’t move easily through plants so they need a... read more

Planting Mixes

Planting Mix
Ancients Rise Mix
8336 Whether they be abandoned heirlooms or wild seedlings, tucked in the woods or growing alongside an old road, apple trees live on for hundreds of... read more
Planting Mix
Blueberry Booster
8321 A blend of granite meal, sulfur, Tennessee brown rock, Penobscot Blend Compost & Peat, and micronutrient-rich rock powder. Brings down the soil pH... read more
Planting Mix
Fall Fruit Tree Prep Mix
8333 To prepare your land in fall or winter for spring fruit-tree planting, use this mix. Without digging a hole, spread one bag on an area 4–6' in... read more
Planting Mix
Fruition Mix
8330 A balanced fertilizer to keep your bearing fruit trees healthy and productive. Gypsum (to maintain optimum calcium levels to promote disease... read more
Planting Mix
Hole-Istic Spring Planting Mix
8324 Recommended for fruit trees at planting time. Formerly known as Fruit Tree Planting Mix. Our own well-balanced blend of soil amendments in a... read more
Planting Mix
Sleepytime Garden Blend
8307 The last of the root vegetables have been tucked into the cellar, and the soil microbes snooze contentedly under a blanket of young winter rye.... read more
Planting Mix
8309 (3-2-2.5) The fertilizer formerly known as Bulb Planting Mix is still perfectly suitable for this purpose, but we are rebranding it to emphasize... read more

Compost and Potting Soil

Compost and Potting Soil
Raw Biochar
8348 Join the carbon-farming revolution. Biochar is the product of heating organic matter in a low-oxygen environment: instead of releasing the carbon... read more