Wicked Organic Blueberry Fertilizer

Purpose-Built for Blueberries. Organic 4-6-4 with the Acid-Soil Micronutrients They Live On

Old Cobblers Farm Wicked Organics Blueberry Fertilizer is a blended organic plant food formulated for blueberries and other acid-loving fruit and shrubs. Blueberries are famously particular: they want acidic soil (roughly pH 4.5–5.5), shallow feeder roots that spread well past the branches, and steady, gentle nutrition. This 4-6-4 is built around exactly that. Its nitrogen is split — of the 4% total, 2.5% is water-insoluble and released slowly by soil microbes, with 1.5% water-soluble for a steadier start — making it a genuine slow-release, non-burning feed safe for those sensitive shallow roots. The 6% phosphate supports root systems and flower-bud formation, and the 4% potash supports stress tolerance and fruit quality.

The part that matters most for blueberries is the acid-soil package: it supplies iron, manganese, and sulfur — the micronutrients that become more available in acidic soil and whose lockup in sweet (high-pH) soil is the usual cause of yellowing leaves and weak growth. The elemental sulfur also works gradually to support the low pH blueberries need. One honest caveat keeps expectations right: blueberries are unusually pH-sensitive, and a fertilizer alone won't rescue genuinely alkaline soil — on high-pH ground, use a soil test and a dedicated acidifier alongside this feed.

It's best fed in fall — blueberry roots stay active well into autumn, building winter hardiness and storing nutrients for spring — with a spring feeding before bloom for berry set. One ingredient note: this blend contains animal protein meals and bone char, so it is not a vegan product, and like other bone- and protein-based feeds it can attract pets; incorporate it and store it securely.

Key Benefits

The blueberry micronutrients — Supplies iron, manganese, and sulfur — the acid-soil micronutrients whose lockup in high-pH soil is the usual cause of blueberry leaf yellowing.

Supports blueberry soil pH — Elemental sulfur works gradually to support the low pH (≈4.5–5.5) blueberries need to thrive and fruit.

Slow-release, non-burning — The 2.5% water-insoluble nitrogen releases slowly through microbial breakdown — steady feeding that won't shock or burn shallow blueberry roots.

Phosphorus and potassium for fruit — 6% phosphate supports root systems and flower-bud formation; 4% potash supports stress tolerance and fruit quality.

Supports bloom and berry set — Properly fed plants in favorable soil set fuller bloom and better fruit — the feed does its part of the picture.

All blueberry types & kin — Works for highbush, lowbush, and rabbiteye blueberries, plus azaleas, rhododendrons, and other acid-lovers.

Where to use it: blueberries (highbush, lowbush, and rabbiteye), plus azaleas, rhododendrons, gardenias, hydrangeas, heaths and heathers, huckleberries, mountain laurels, raspberries, and other acid-loving plants.