Guaranteed Analysis
Nutrient Breakdown
N · Nitrogen8%
Provides 8% nitrogen (from urea) for steady leaf growth and shoot extension without excessive vegetative vigor that reduces fruit quality or invites disease
P · Phosphorus0%
N/A — Contains no phosphorus. Designed for established plantings where soil phosphorus is already adequate. Adding unnecessary phosphorus can interfere with zinc and iron uptake.
K · Potassium16%
Supplies a strong 16% potassium (from muriate of potash) to improve fruit size, color, sugar content, firmness, winter hardiness, and overall plant vigor
Derived from: Urea, Potassium Chloride (Muriate of Potash), Silicon Dioxide. Includes micronutrients.
Overview
What It Is
This 8-0-16 formula is the general-purpose version of Old Cobblers Farm's Apple Tree Fertilizer—both share the same Green Mountain Fertilizer formulation. The three-ingredient blend (urea, muriate of potash, silicon dioxide with micronutrients) provides exactly what established plantings need without anything they don't.
The zero-phosphorus design reflects responsible nutrient management. Phosphorus binds tightly to soil particles and accumulates year after year. Many established gardens have soil P well above optimal, and continued application provides no benefit while increasing waterway pollution risk. The 8% nitrogen provides maintenance-level growth support, and the 16% potassium replenishes the nutrient crops export in the largest quantities through harvest.
Crop Fit
Best For
Fruit TreesEstablished OrchardsGrapesBerry PatchesEstablished GardensHay FieldsPasturesLawns
This formula excels in established plantings where years of cultivation have built up soil phosphorus. Apple and pear trees, grapes, and berry bushes all benefit from the high K-to-N ratio during fruiting. Hay fields and pastures receiving regular manure rarely need additional phosphorus but frequently need potassium. Lawns in states with phosphorus restrictions can use this formula freely.
Application Rates
How Much to Use
| Garden & beds | 0.5-1 lb per 100 sq ft under the canopy or across established beds |
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| Lawn | 3-5 lbs per 1,000 sq ft for potassium-deficient lawns that don't need phosphorus |
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| Trees & shrubs | 0.5-1 lb per inch of trunk diameter, broadcast evenly under the canopy from 1 foot from the trunk to the drip line |
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| Containers | 2 tablespoons per container for dwarf trees or large potted plants (15+ gallons) |
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| Frequency | 1-2 applications per year: primary in early spring before active growth, optional light fall application after harvest for established plantings |
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Step by Step
How to Apply
1Soil Test
Confirm with a soil test that phosphorus is adequate but potassium needs supplementation.
2Garden Rate
Broadcast 0.5–1 lb per 100 sq ft in early spring for gardens and established beds.
3Fruit Tree Rate
For fruit trees, apply 0.5–1 lb per inch of trunk diameter under the canopy from 1 foot out to the drip line.
4Lawn Rate
For lawns, apply 3–5 lbs per 1,000 sq ft with a calibrated spreader for even distribution.
5Water In
Water thoroughly after application to dissolve granules and move nutrients into the root zone.
6Optional Side-Dress
Optional mid-season side-dress for heavy-producing crops at half the initial rate to sustain fruiting.
Apply in early spring before active growth. For orchards, broadcast under the tree canopy from 1 foot out to the drip line. For garden beds, spread evenly and lightly incorporate. For hay fields and pastures, broadcast at 200-400 lbs per acre in early spring. For lawns, use a calibrated spreader at 3-5 lbs per 1,000 sq ft. Apply using the same rates and methods as Old Cobblers Farm™ Apple Tree Fertilizer.
Handling & Timing
Safety & Season
Safety & Storage
Wear protective gloves and eye protection during handling. Avoid breathing dust. Wash hands thoroughly after handling. Store in a cool, dry, well-ventilated area. Keep sealed when not in use. Prevent entry to sewers and surface waters. Keep out of reach of children and pets.
Seasonal Notes
Spring: Primary application before active growth in orchards, gardens, and lawns. Summer: Optional mid-season side-dress for heavy-fruiting crops. Fall: Can apply post-harvest to orchards and perennials for winter hardiness. Winter: No application. Plan soil testing.
In Context
How It Compares
The 8-0-16 fills the gap between straight potash (0-0-60) and complete fertilizers by providing nitrogen and potassium without unnecessary phosphorus. Compared to 0-0-60 applied alone, this adds nitrogen for growth support. This formula is suitable for lawns where soil tests show adequate phosphorus—many states restrict phosphorus in lawn fertilizers. This is the same formulation as Old Cobblers Farm™ Apple Tree Fertilizer.
Answers
Frequently Asked Questions
What is 8-0-16 fertilizer used for?
8-0-16 fertilizer is a zero-phosphorus formula with elevated nitrogen and potassium designed for established plantings in soils that already have sufficient phosphorus. The higher nitrogen (8%) compared to 6-0-16 provides more vigorous foliage growth, while the high potassium (16%) strengthens plants against environmental stress. It is commonly used for lawn maintenance, fruit tree care, and agricultural crops where phosphorus is not needed but nitrogen and potassium are. Old Cobblers Farm™ Wicked Growth 8-0-16 Fertilizer delivers targeted nutrition for healthy, resilient plants without contributing to phosphorus buildup in the soil.
What is the difference between 6-0-16 and 8-0-16 fertilizer?
Both are zero-phosphorus formulas with high potassium, but 8-0-16 provides more nitrogen (8% vs 6%). Choose 8-0-16 when plants need stronger vegetative growth support — for example, actively growing lawns, fruit trees during canopy development, or crops in their vegetative stage. Choose 6-0-16 when you want minimal nitrogen input with maximum potassium, such as for stress conditioning or fall hardening. Both are excellent choices for established plantings in phosphorus-rich soils. Old Cobblers Farm™ Wicked Growth offers both options so you can match the formula to your specific growing conditions.
Is 8-0-16 good for apple trees?
Yes, 8-0-16 is an excellent choice for apple trees, particularly mature trees in soils with adequate phosphorus. The nitrogen promotes healthy leaf growth and canopy density, which drives photosynthesis and fruit production. The high potassium directly improves fruit size, sweetness, color, and storage quality. Apply 1–2 pounds per inch of trunk diameter in early spring before bud break, spreading evenly under the drip line. Old Cobblers Farm™ Wicked Growth Apple Tree Fertilizer uses this same 8-0-16 ratio, delivering the targeted nutrition apple trees need for healthier growth and bigger, sweeter harvests.
Can I use zero-phosphorus fertilizer on vegetables?
Yes, zero-phosphorus fertilizers like 8-0-16 work well on established vegetable gardens where soil tests show phosphorus levels are already adequate or high. Many gardens that have received regular fertilization or compost applications for several years accumulate excess phosphorus. In these situations, continuing to add phosphorus can actually inhibit nutrient uptake. Switching to a zero-phosphorus formula keeps your soil balanced and your plants healthier. Old Cobblers Farm™ Wicked Growth 8-0-16 Fertilizer provides the nitrogen and potassium vegetables need without adding unnecessary phosphorus.
When should I use a high potassium fertilizer?
Use high potassium fertilizers when plants are fruiting, under environmental stress, or heading into dormancy. Potassium improves fruit quality, strengthens cell walls, regulates water within the plant, and enhances disease and cold resistance. It is especially valuable during mid-to-late season when crops are setting and ripening fruit, and in fall when lawns and perennials need to build winter hardiness. Soil tests showing low potassium levels are another clear signal. Old Cobblers Farm™ Wicked Growth 8-0-16 Fertilizer delivers a strong dose of potassium (16%) to support plant strength exactly when it matters most.
Does 8-0-16 fertilizer work on lawns?
Yes, 8-0-16 is an effective lawn fertilizer for established turf in phosphorus-adequate soils. The 8% nitrogen promotes thick, green grass, while the 16% potassium strengthens root systems and improves tolerance to drought, heat, cold, and traffic. It is especially well-suited for summer and fall applications when lawns need resilience more than rapid growth. Many municipalities restrict phosphorus use in lawn fertilizers due to water quality concerns, making zero-phosphorus formulas like 8-0-16 both practical and environmentally responsible. Old Cobblers Farm™ Wicked Growth 8-0-16 Fertilizer keeps lawns strong and green without excess phosphorus.
How much potassium do fruit trees need?
Fruit trees generally need 0.5–1.5 pounds of actual potassium (K₂O) per tree per year, depending on size and crop load. Trees under heavy fruit production require more potassium because each fruit removes significant amounts during development. Signs of potassium deficiency include leaf edge browning, small fruit, poor color development, and reduced winter hardiness. Soil testing is the best way to determine exact needs. With 16% potassium, 8-0-16 fertilizer provides a concentrated dose per application. Old Cobblers Farm™ Wicked Growth 8-0-16 Fertilizer delivers the potassium fruit trees need for bigger, sweeter, and longer-storing harvests.
