Similar to: GS Plant Foods Cal-Mag

Top Picks

Greenway Biotech Boric Acid
Top Pick

Best high volume choice for budget conscious homeowners seeking purity.

This high-purity micronutrient provides a precise, water-soluble solution for correcting boron deficiencies in soil and hydroponic systems. Beyond plant health, it serves as an effective natural deterrent against common household pests like ants and cockroaches.

High Purity

Water Soluble

Pest Deterrent

Organic

E.B. Stone Organics Bat Guano
Runner-Up

Best organic nitrogen boost for serious vegetable and flower gardeners.

This is the secret weapon for anyone needing an aggressive nitrogen boost to jumpstart leafy growth. It’s an old-school, organic powerhouse that works fast, though you’ll need to handle the powder carefully to avoid the mess. It’s the most reliable way to feed hungry plants without relying on synthetic chemicals.

Fast Acting

Versatile

Organic

Down To Earth Gypsum
Best Value

Best soil amendment for organic gardeners seeking efficient nutrient delivery.

This fine-milled gypsum is the ultimate fix for stubborn soil structure without the headache of pH fluctuations. Its ultra-fine powder dissolves seamlessly into irrigation systems, trading the mess of granular alternatives for professional-grade, immediate nutrient delivery.

Non-clogging

Nutrient-rich

pH-neutral

Organic-certified