• Wear chemical-resistant gloves when handling granules
• Wear safety glasses or goggles to protect against dust
• Use a dust mask or N95 respirator in dusty application conditions
• Wash hands thoroughly with soap and water after handling

• Store in a cool, dry place in the original sealed container
• MAP is hygroscopic — reseal tightly after each use to prevent clumping
• Keep away from direct sunlight and heat sources
• Store away from children and pets
• Do not store near incompatible materials such as strong acids or bases

• This granular grade is intended for direct soil application only — do not use in fertigation systems, drip injectors, stock tanks, or foliar sprays
• Do not place granules in direct contact with seeds or tender roots
• Keep granules away from direct contact with plant stems and foliage to prevent burn
• Do not apply on hard surfaces or near waterways where granules can wash off
• Do not apply to waterlogged or frozen soils
• Water in thoroughly after application

• Eye contact: Flush with clean water for 15 minutes. Seek medical attention if irritation persists
• Skin contact: Wash affected area thoroughly with soap and water
• Ingestion: Do not induce vomiting. Contact Poison Control (1-800-222-1222) or seek medical attention immediately
• Inhalation: Move to fresh air. Seek medical attention if symptoms persist

Refer to the Safety Data Sheet (SDS) for complete safety information.

MAP 11-52-0 (this product) is a granular form designed for direct soil application — broadcasting, side dressing, banding, and pre-plant incorporation. Granules dissolve into the soil profile after irrigation or rainfall.

MAP 12-61-0 is a 100% water-soluble powder with 61% available phosphate (P₂O₅), formulated for complete dissolution in water. Use it for fertigation, foliar feeding, and hydroponic systems where a liquid-soluble phosphorus source is required.

For a deeper comparison, see our guide on choosing the best phosphorus fertilizer.

No. This granular grade is intended for soil application rather than liquid feeding. It is not formulated for complete dissolution in water and should not be used in fertigation systems, drip injectors, or stock tanks — undissolved material can clog equipment. For fertigation or foliar spraying, use our MAP 12-61-0 (Water Soluble) instead.

Vegetables: Work into soil before planting, then side dress when plants begin flowering. For root crops, apply at bed preparation.

Fruit trees: Apply in early spring before bud break, and optionally post-harvest to restore nutrient reserves. Split applications for young trees — 2–3 smaller doses are preferred over one large application.

Ornamentals: Spring bloomers benefit from fall application; summer bloomers from early spring application.

Lawns: Cool-season grasses in early fall, warm-season grasses in late spring. Incorporate before seeding for new lawns.

Over time, yes — the ammoniacal nitrogen in MAP can contribute to gradual soil acidification as nitrification occurs. This may be beneficial in alkaline soils (pH 7.5+) where high pH reduces phosphorus and micronutrient availability. In already acidic soils (below pH 6.0), monitor pH periodically and apply lime if needed. A soil test before application is always recommended.

Calcium and phosphate ions react when in direct concentrated contact, forming insoluble calcium phosphate that reduces the availability of both nutrients. Apply them at separate times or in separate passes, and allow irrigation water to move them independently through the soil. For crops with high calcium demand — tomatoes, peppers, squash — apply calcium nitrate as a separate side dress or foliar application. Learn more in our article on the function of phosphorus in plants.

Coverage depends on application rate and method. General guidelines:

• 2 lb bag — small raised beds or container soil amendment (covers ~40–67 sq ft)
• 5 lb bag — home vegetable garden or flower beds (covers ~100–167 sq ft)
• 10 lb bag — larger home garden or small orchard (covers ~200–333 sq ft)
• 25 lb bag — established garden, small lawn, or multi-tree orchard (covers ~500–833 sq ft)
• 50 lb bag — field plots, large orchards, or commercial use (~1,000–1,667 sq ft or ~0.17 acre at 300 lbs/acre)

Use the MAP 11-52-0 Calculator above for precise amounts based on your area and crop type.

Crops with high phosphorus demands see the most benefit: flowering annuals (petunias, marigolds, zinnias), bulbs (tulips, daffodils), roses, fruiting vegetables (tomatoes, peppers, squash, melons), root vegetables (potatoes, carrots, beets, onions), and commercial crops (corn, soybeans, cotton, tree fruits). For more information, see our article on fertilizers that improve fruit yield.

Note: Phosphorus-sensitive plants such as proteas and grevilleas should receive reduced rates or phosphorus-free alternatives.

• Manufactured and repackaged in California, USA at our Madera facility
• Independently lab tested for heavy metal content for safe use in food gardens
• Registered with the California Department of Food and Agriculture (CDFA)
• Nutrient analysis guaranteed on label per CDFA requirements

If you're not completely satisfied with your purchase, we offer a 90-day money-back guarantee. Simply return the unused portion in its original packaging and we'll process a full refund — no questions asked.

• High-analysis formula reduces the total volume of product needed per application
• Support for responsible nutrient stewardship — apply based on soil test results when possible
• Transitioning to compostable packaging solutions

1% of all profits go to our foundation, focused on improving educational opportunities for children.

Family-owned since 1989. Based in Madera, California, we've been making professional-grade fertilizers and soil amendments available to home gardeners and commercial growers alike for over 35 years.