Copper Sulfate Fertilizer Crystals 25% Cu (99% Pentahydrate)

Greenway Biotech Copper Sulfate Crystals are copper sulfate pentahydrate (CuSO₄·5H₂O), 99% pure, guaranteeing 25% copper (Cu), so each pound supplies a quarter pound of copper. The fine blue crystals dissolve readily in water and are sold as a copper fertilizer for correcting a deficiency confirmed by plant tissue analysis, with a soil test on organic soils.

Copper shortages are uncommon and occur mainly on peat and muck soils and some sandy soils, in crops such as small grains, onion, lettuce, and carrot. University broadcast rates run from 4 to 13 lb of copper per acre depending on crop and soil (16 to 52 lb of this product), applied once and lasting several years. The margin between deficiency and toxicity is narrow, so test first and never apply on a schedule.

Sold only as a fertilizer; not registered as a pesticide. Packed in Madera, California, in 1 to 50 lb sizes.