Wicked Organics Organic Organic OMRI Listed

Blueberry Fertilizer

NPK 4-6-4

Organic Blueberry Fertilizer 4-6-4 is a natural fertilizer crafted from mineral and organic ingredients, specially designed for blueberries and other acid-loving fruit and ornamental plants. The 4-6-4 NPK ratio — with 4% nitrogen split between water soluble and water insoluble forms, 6% phosphorus for root and flower development, and 4% potassium for fruit quality and winter hardiness — delivers exactly the nutrition blueberries need without the risk of root burn from synthetic fertilizers. The natural ingredient base of elemental sulfur, protein meals, bone char, and natural potash sources feeds the plants while maintaining the acidic soil pH that blueberries require for optimal nutrient uptake and fruit production. Blueberries are particularly sensitive to over-fertilization and pH imbalances — this organic formula provides the gentle, sustained feeding they need for abundant harvests year after year. Old Cobblers Farm™ Wicked Organics Organic Blueberry Fertilizer is the natural choice for home growers and organic berry producers alike.

Application Rates FAQs
Nutrient Profile
WO-BLUEBERRY
4–6–4
Blueberry Fertilizer
Derived From
  • Total Nitrogen (N) 4.0% (1.5% Water Soluble Nitrogen, 2.5% Water Insoluble Nitrogen), Available Phosphate (P2O5) 6.0%, Soluble Potash (K2O) 4.0%. Derived from: Elemental Sulfur, Animal Protein Meals, Vegetable Protein Meals, Natural Sulfate of Potash, Natural Nitrate of Soda, Bone Char
4-6-4
NPK Ratio
Organic
Formula Type
Twice per year — fall (after harvest) and spring (before bloom). If once, choose fall.
Feeding Frequency
—
Compatible Plants
What It Is

Understanding 4-6-4

Organic Blueberry Fertilizer 4-6-4 is a crop-specific organic fertilizer formulated for the unique nutritional and pH requirements of blueberry bushes and similar acid-loving plants. Blueberries need specific nutrients — iron, manganese, and sulfur — that become more available in acidic soils (pH 4.5-5.5). Soils high in calcium, magnesium, or sodium can inhibit blueberry growth, causing chlorosis (yellowing leaves), stunted growth, and poor fruiting.

This fertilizer addresses both nutrition and pH management simultaneously. The elemental sulfur component actively lowers soil pH over time, while the organic protein meals and bone char provide a slow, steady release of macro and micronutrients that match the blueberry's moderate feeding requirements. The organic matter in the ingredients also improves soil structure, moisture retention, and beneficial microbial activity — all critical for the shallow, fibrous root system blueberries depend on.

N
Nitrogen — 4%

Provides 4% total nitrogen (1.5% water soluble, 2.5% water insoluble) for steady vegetative growth and leaf expansion that powers fruit production without burning shallow blueberry roots.

P
Phosphorus — 6%

Delivers 6% available phosphate (P2O5) to promote strong root establishment, increased flower bud formation, and heavier fruit set in blueberry bushes.

K
Potassium — 4%

Supplies 4% soluble potash (K2O) to improve fruit quality, winter hardiness, and disease resistance — critical for perennial blueberry plantings.

Recommended Plants

Best For

Blueberries
Raspberries
Huckleberries
Azaleas
Rhododendrons
Hydrangeas
Gardenias
Cranberries

Growing Detail

While formulated specifically for blueberries, this fertilizer works across all acid-loving plants that share similar pH and nutrient requirements. Blueberries (highbush, lowbush, and rabbiteye varieties) are the primary target — the gentle organic nutrition protects their sensitive shallow roots while the sulfur maintains the low pH they demand. Raspberries and huckleberries share similar acid-soil preferences and respond well to this formula. Ornamental acid-loving plants including azaleas, rhododendrons, hydrangeas, gardenias, heaths, heathers, mountain laurels, ferns, and lupine all thrive with the same 4-6-4 organic nutrition profile.
Dosing Guide

Application Rates

Garden Beds
1 lb per 2 ft of crown diameter
Container / Pot
1 tbsp per gallon of soil
Water Mix
N/A — granular application
Lawn
N/A — formulated for blueberries and acid-loving plants, not turf
Trees
1 lb per 2 ft of crown diameter, broadcast under the drip line
Per Acre
870-1,300 lbs per acre
Frequency
Every 2-4 weeks

How to Apply

Seasonal Notes

Fall is the preferred and most important application window — apply after harvest to build winter hardiness and store nutrients for next spring's growth. Spring application supports the critical flush of new shoots, leaves, and flower buds that determine the season's fruit yield. Both applications together produce the best results. Avoid summer application during fruit ripening. Not applied in winter when ground is frozen.
How It Compares

Side by Side

Compared to the Wicked Organics Organic Evergreen Fertilizer, this product shares the same 4-6-4 NPK and ingredient base but is marketed and positioned specifically for blueberry growers with crop-specific application guidance. Versus synthetic blueberry fertilizers (like ammonium sulfate), this organic formula provides gentler, sustained feeding that won't damage blueberry's shallow, sensitive root system. Compared to cottonseed meal or sulfur-only amendments, the complete 4-6-4 formula provides balanced P and K nutrition that single-ingredient approaches lack.

Safety & Storage

Store in a cool, dry place in original packaging. Natural organic fertilizer — safe for use around children and pets when applied as directed. Wash hands after handling. May attract animals due to protein meal content — keep sealed between uses.

Got Questions?

Frequently Asked

  • The best organic blueberry fertilizer provides balanced nutrition from natural, slow-release ingredients while supporting the acidic soil conditions blueberries require. An organic formula made from elemental sulfur, protein meals, bone char, and natural sulfate of potash delivers steady NPK nutrition and helps maintain low soil pH through the sulfur component. Organic fertilizers also build soil biology, which improves nutrient cycling in the root zone. Old Cobblers Farm™ Wicked Organics Organic Blueberry Fertilizer is specifically formulated for organic blueberry production with natural ingredients that support both plant and soil health.
  • Apply organic blueberry fertilizer in early spring when new growth begins and optionally again after harvest in mid-summer. Spread 1–2 cups per established bush around the drip line, lightly incorporate into the top inch of mulch or soil, and water thoroughly. For young bushes, use ½–1 cup. Organic fertilizers release nutrients slowly, so apply 2–4 weeks before you want peak nutrition to give soil microbes time to process the ingredients. Old Cobblers Farm™ Wicked Organics Organic Blueberry Fertilizer provides gentle, season-long feeding from natural ingredients.
  • Organic blueberry fertilizers that contain elemental sulfur help maintain and lower soil pH over time. Soil bacteria convert elemental sulfur into sulfuric acid, which gradually acidifies the root zone — exactly what blueberries need. This natural acidification process is slower and more gentle than applying synthetic acids, providing a sustained pH-lowering effect. Regular application of sulfur-containing organic fertilizer helps keep soil in the 4.5–5.5 pH range blueberries require. Old Cobblers Farm™ Wicked Organics Organic Blueberry Fertilizer includes elemental sulfur for natural soil acidification.
  • Wicked Organics Organic Blueberry Fertilizer is formulated from elemental sulfur, vegetable protein meals, animal protein meals, natural sulfate of potash, nitrate of soda, and bone char. Elemental sulfur acidifies soil naturally. Protein meals provide slow-release nitrogen. Bone char contributes phosphorus and calcium. Sulfate of potash delivers chloride-free potassium essential for berry quality. All ingredients are OMRI-Listed for certified organic use. Old Cobblers Farm™ Wicked Organics uses only high-quality natural ingredients specifically selected for the unique nutritional and pH requirements of blueberry bushes.
  • Yes, organic blueberry fertilizer works well on other acid-loving berry plants including raspberries, blackberries, cranberries, and huckleberries. It also benefits acid-loving ornamentals like azaleas, rhododendrons, and camellias. However, berries that prefer neutral soil (like strawberries) may not need the soil-acidifying sulfur component. For strawberries, consider Wicked Organics formulas without added sulfur. Old Cobblers Farm™ Wicked Organics Organic Blueberry Fertilizer is ideal for any berry or plant that thrives in acidic soil conditions.
  • Fertilize blueberries organically 1–2 times per year. The primary application should be in early spring before new growth begins, with an optional second application after harvest in mid-summer to support flower bud formation for next year's crop. Organic fertilizers release nutrients slowly, so fewer applications are needed compared to synthetic programs. Supplement with elemental sulfur as needed based on soil pH testing to maintain the 4.5–5.5 range. Old Cobblers Farm™ Wicked Organics Organic Blueberry Fertilizer provides sustained nutrition from each application for simpler organic blueberry care.
  • Yes, Old Cobblers Farm™ Wicked Organics Organic Blueberry Fertilizer is OMRI-Listed, meaning it has been reviewed and approved by the Organic Materials Review Institute for use in certified organic production. OMRI certification verifies that all ingredients meet strict organic standards with no synthetic chemicals or prohibited substances. This gives home gardeners and certified organic blueberry growers confidence that they are using a genuinely organic product. Old Cobblers Farm™ Wicked Organics carries the OMRI seal across its entire organic fertilizer lineup.

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