Cutting Edge Solutions Uncle John’s Blend is a liquid potassium supplement with a guaranteed analysis of 0-0-2 (N-P-K), supplying 2.0% soluble potash (K) plus 0.1% iron (Fe), in a 2.5 gallon container. The maker positions it as a supplement for all stages of growth that is most critical in the flowering stage for nutrient mobilization and metabolism. This page gives the maker’s published guaranteed analysis, compatibility, and mix rates, and is honest about the details the maker does not publish. It is a supplemental additive, not a standalone base nutrient.
What it is
Uncle John’s Blend is one of Cutting Edge Solutions’ Strength-family additives — a liquid potassium supplement rather than a complete feed. The maker describes it as a product that combines essential trace micronutrients with potassium to support and enhance the genetic potential of plants, carrying a guaranteed analysis of 0-0-2. Its nutrients are derived from ferrous sulfate and potassium sulfate, and this listing is the 2.5 gallon size, one of several the maker offers.
Guaranteed analysis and specifications
| Guaranteed analysis (N-P-K) | 0-0-2 |
|---|---|
| Soluble Potash (K) | 2.0% |
| Iron (Fe) | 0.1% |
| Derived from | Ferrous Sulfate, Potassium Sulfate |
| Form | Liquid supplement / additive |
| Container size | 2.5 gallon |
The 0-0-2 label reflects a potassium-and-micronutrient supplement, not a nitrogen or phosphorus source — it is meant to sit alongside a complete base program, not replace it.
Why potassium matters
Potassium is one of the primary plant macronutrients. University-extension guidance notes that potassium is vital to photosynthesis and protein synthesis, and that it has a fundamental role in regulating leaf stomata openings and controlling water use, particularly under dry conditions. Extension guidance also describes potassium as activating a wide range of enzymatic and plant-hormonal reactions. That physiology is why a potassium-focused supplement is often reached for during flowering and heavy fruiting, when demand for potassium climbs — though the specific efficacy of this product for any crop is the maker’s positioning, not an independent finding.
Why choose it
- Targeted potassium and iron. With 2.0% soluble potash and 0.1% iron, it is a focused supplement rather than a broad-spectrum feed.
- Built for flowering support. The maker positions it as most critical in the flowering stage for nutrient mobilization and metabolism.
- Wide system compatibility. Cutting Edge states it is versatile enough for all types of fertigation systems, including drip irrigation and recirculating hydroponics, and effective as a foliar spray during the vegetative growth phase.
- Designed to layer into a program. The maker says it is designed to integrate smoothly with all commercial nutrient programs.
Best uses
- Flowering-stage potassium boosting. The maker calls it a supplement across all growth stages that matters most during flowering.
- Recirculating and drip fertigation. It is stated to suit drip irrigation and recirculating hydroponic systems.
- Foliar feeding in veg. The maker also lists foliar application in the vegetative and transition phases.
Compatibility
Per the maker, Uncle John’s Blend is versatile for all types of fertigation systems, including drip irrigation and recirculating hydroponics, and works as a foliar spray in the vegetative phase, and is designed to integrate with commercial nutrient programs. As a supplement it is intended to run alongside a complete base feed, not on its own.
Dosing and application (maker directions)
Follow the maker’s label directions. Cutting Edge’s published rates are:
- Reservoir feeding, all phases of growth: mix 10 mL of Uncle John’s Blend per gallon of water.
- Injection feeding, all phases of growth: set the ratio at 1:375, or 0.26%.
- Foliar feeding, vegetative and transition phases: mix 7 mL per gallon of water.
Always integrate a supplement gradually and monitor your solution, as with any additive layered onto a base program.
Comparison
| Attribute | Uncle John’s Blend 0-0-2 | A complete base nutrient |
|---|---|---|
| Role | Potassium / micronutrient supplement | Standalone primary feed |
| Guaranteed analysis | 0-0-2 | Supplies N, P and K |
| Used with a base feed? | Yes — layered on | No — it is the base |
Uncle John’s Blend is not a substitute for a base nutrient; it adds targeted potassium and iron to an existing program.
Where it fits
For more supplements and boosters, browse the growth & bloom boosters category. Related additives and supplements include:
- Earth Juice Hi-Brix Molasses for Plants — a carbohydrate additive for microbial and bloom support.
- Athena Cal Mag (1 gal) — a calcium-magnesium supplement for another common deficiency.
- General Organics CaMg+ Calcium Magnesium Supplement — an organic cal-mag supplement.
- Maxicrop Soluble Seaweed Powder — a seaweed-based plant supplement.
- PureCrop1 (2.5 gal) — a multi-purpose foliar and root additive.
- Flying Skull Z7 Enzyme Cleanser (5 Gallon) — an enzyme cleaner for root zones and reservoirs.
Frequently asked questions
What is the NPK? The maker’s guaranteed analysis is 0-0-2, with 2.0% soluble potash and 0.1% iron.
How do I use it in a reservoir? The maker says to mix 10 mL per gallon of water for all phases of growth.
Can it be used as a foliar spray? Yes — the maker directs 7 mL per gallon of water for foliar feeding in the vegetative and transition phases.
Who this is for — and who should skip it
Suited: growers who already run a complete base nutrient and want a targeted 0-0-2 potassium and iron supplement, especially through flowering, in drip, recirculating, or foliar applications.
Not for / its limits: it is a supplement, not a standalone feed — with no nitrogen or phosphorus it cannot carry a crop on its own. Growers wanting a single complete nutrient should choose a base feed instead.
HELD (not stated because not sourced): the live retail price (the storefront price field is the source of truth at deploy); the maker SKU / part number; the warranty term (held per M-05); shelf life; net weight and density; pH and EC of the concentrate; and the full trace-micronutrient list beyond the guaranteed potassium and iron (the maker page names only K and Fe in the guaranteed analysis).
Ready to top up potassium? Add to cart, or talk to a grower about fitting Uncle John’s Blend into your feed schedule.
Sources
- Cutting Edge Solutions — Uncle John’s Blend 0-0-2 maker product page (HTTP 200, retrieved 2026-07-08 via WAF-immune fetch; PRIMARY source): guaranteed analysis 0-0-2, Potassium (K) 2.0%, Iron (Fe) 0.1%, derived from Ferrous Sulfate and Potassium Sulfate; available sizes including 2.5 gallon; compatibility with fertigation, drip irrigation, recirculating hydroponics, and foliar; mix rates (10 mL/gal reservoir all phases; 1:375 or 0.26% injection; 7 mL/gal foliar veg/transition): https://www.cuttingedgesolutions.com/products/uncle-johns-blend
- Michigan State University Extension — “Potassium: the overlooked nutrient in crop production” (HTTP 200, university-extension, retrieved 2026-07-08; general potassium physiology): potassium is vital to photosynthesis and protein synthesis, has a fundamental role in regulating leaf stomata openings and controlling water use particularly under dry conditions, and activates enzymatic and plant-hormonal reactions: https://www.canr.msu.edu/news/potassium_the_overlooked_nutrient_in_crop_production
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