Guaranteed Analysis
Nutrient Breakdown
N · Nitrogen6%
Provides 6% nitrogen from urea for moderate vegetative support without excessive leaf growth, allowing plants to focus energy on fruit production, tuber development, and crop quality.
P · Phosphorus0%
N/A — Contains no phosphorus. This zero-P formula is designed for soils that already test adequate or high in phosphorus, or where phosphorus runoff restrictions apply. Pair with 0-46-0 Triple Superphosphate if phosphorus is also needed.
K · Potassium16%
Delivers 16% potassium from muriate of potash to strengthen cell walls, improve drought and disease resistance, enhance fruit size, flavor, and sugar content, boost winter hardiness, and improve storage quality in root crops.
Derived from: Urea, Potassium Chloride (Muriate of Potash), Silicon Dioxide. Includes micronutrients.
Overview
What It Is
6-0-16 is a targeted nitrogen-potassium fertilizer with zero phosphorus, formulated from the same ingredient base as the Wicked Growth Apple Tree Fertilizer and 8-0-16 Zero Phosphorus formula: Urea, Potassium Chloride (Muriate of Potash), and Silicon Dioxide with included micronutrients. The 6% nitrogen from urea provides moderate vegetative support, while the 16% potassium oxide (K2O) from muriate of potash delivers concentrated potassium for crop quality and plant resilience.
The zero-phosphorus design addresses a common problem in established growing areas. Unlike nitrogen and potassium which plants consume heavily and which can leach from soil, phosphorus binds to soil particles and accumulates over time. Soil tests frequently reveal adequate or excessive phosphorus in gardens and fields that have received years of balanced fertilizer applications. Adding more phosphorus provides no plant benefit and increases the risk of phosphorus runoff into waterways.
Compared to the 8-0-16 formula, the 6-0-16 reduces nitrogen by 25% while maintaining the same potassium level — a ratio better suited for fruiting crops where you want to minimize vegetative push and maximize reproductive output.
Crop Fit
Best For
TomatoesPeppersCucumbersMelonsSquashPotatoesRoot VegetablesGrapes
High-yield fruiting crops are the primary targets for 6-0-16. Tomatoes and peppers are heavy potassium feeders — adequate K improves fruit size, flavor, firmness, and blight tolerance. Cucumbers and melons produce sweeter, more uniform fruit with potassium supplementation. Squash develops stronger vines and larger fruit. Potatoes depend on potassium for tuber size, starch content, and storage quality — and often grow in fields with accumulated phosphorus from years of heavy fertilization. Root vegetables like carrots and beets use potassium for root expansion and sugar development. Grapes benefit from potassium for sugar accumulation, color development, and winter hardiness. All of these crops commonly grow in soils where phosphorus is already adequate, making the zero-P formula both agronomically and environmentally appropriate.
Application Rates
How Much to Use
| Garden & beds | 0.5-1 lb per 100 sq ft for established garden beds and high-yield crop plantings |
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| Lawn | 3-5 lbs per 1,000 sq ft for potassium-deficient lawns that do not 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 large potted plants (15+ gallons) |
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| Frequency | 1-2 applications per year: primary in early spring before active growth, optional mid-season application for heavy-feeding fruiting crops |
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Step by Step
How to Apply
1Soil Test
Get a soil test to confirm phosphorus is adequate and potassium needs supplementing. This zero-phosphorus formula avoids P overload.
2Calculate Rate
Calculate coverage based on your area and the recommended application rate for your crop type.
3Broadcast / Side-Dress
Broadcast evenly over the soil surface or side-dress along crop rows during the growing season.
4Incorporate
Work into the top 2–3 inches of soil if applying before planting to place potassium in the root zone.
5Water In
Water thoroughly after application to dissolve granules and carry nutrients to the root zone.
6Avoid Contact
Do not apply directly to plant roots, stems, or foliage to prevent burn damage.
7Mid-Season Reapply
Reapply mid-season for heavy-feeding fruiting crops (tomatoes, peppers, melons) if soil tests warrant additional potassium.
For garden beds, broadcast 0.5-1 lb per 100 sq ft and work into the top 4-6 inches before planting, or side-dress established plants by applying in a band 4-6 inches from stems. For fruit trees and grape vines, scatter from 1 foot from the trunk to the drip line at 0.5-1 lb per inch of trunk diameter. For potatoes and root crops, band application 2-3 inches to the side and below the seed piece at planting is most efficient. For commercial acreage, apply 200-400 lbs per acre based on soil test potassium recommendations. Water in thoroughly after every application — the muriate of potash component has a moderate salt index and can cause root irritation if left concentrated near plant tissue. Always base application rates on current soil test results.
Handling & Timing
Safety & Season
Safety & Storage
Wear protective gloves and eye protection during handling. Avoid breathing dust — use a NIOSH-approved dust respirator if applying in windy conditions. 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 planting when soil is workable. Ideal for garden prep, potato planting, and fruit tree feeding. Summer: Side-dress heavy-fruiting crops mid-season when potassium demand peaks during fruit development. Apply to potatoes at hilling. Fall: Apply to perennial crops, grapes, and fruit trees to boost winter hardiness and storage quality. Winter: Do not apply to frozen ground or dormant plants.
In Context
How It Compares
The 6-0-16 provides 25% less nitrogen than the 8-0-16 Apple Tree formula while maintaining the same potassium concentration — better for high-yield crop production where restrained vegetative growth is preferred. Both use the same ingredient base (urea, MOP, silicon dioxide). Versus straight potash (0-0-60), the 6-0-16 adds nitrogen so you do not need a separate N application. Compared to balanced fertilizers like 10-10-10 or 19-19-19, the zero-phosphorus design prevents unnecessary P accumulation. Versus the 8-16-16, the 6-0-16 eliminates phosphorus entirely for sites where P is already sufficient.
Answers
Frequently Asked Questions
What is 6-0-16 fertilizer used for?
6-0-16 fertilizer is a zero-phosphorus, high-potassium blend designed for soils that already have adequate phosphorus levels but need nitrogen and potassium. It is especially popular for established lawns, high-yield crops, and turf management programs where phosphorus runoff is a concern. The nitrogen (6%) promotes steady green growth without excessive surge, while the high potassium (16%) strengthens plant cells, improves drought tolerance, and enhances disease resistance. Old Cobblers Farm™ Wicked Growth 6-0-16 Fertilizer is ideal for growers who want to maximize yield and plant resilience without adding unnecessary phosphorus to the soil.
Why would I use a zero-phosphorus fertilizer?
Zero-phosphorus fertilizers like 6-0-16 are used when soil tests show adequate or excessive phosphorus levels. Continuing to add phosphorus to already-sufficient soils can lead to nutrient imbalances that inhibit the uptake of iron, zinc, and other micronutrients. Excess phosphorus can also contribute to water pollution through runoff. Many established lawns and gardens have built up sufficient phosphorus over years of fertilization and only need nitrogen and potassium for maintenance. Old Cobblers Farm™ Wicked Growth 6-0-16 Fertilizer delivers targeted nitrogen and potassium without phosphorus, keeping your soil balanced and your plants thriving.
Is 6-0-16 good for lawns?
Yes, 6-0-16 is an excellent lawn fertilizer, especially for established turf that already has adequate soil phosphorus. The nitrogen promotes green color and density, while the high potassium strengthens grass against drought, heat, disease, and heavy traffic. It is particularly effective as a summer stress conditioner or fall hardener when lawns need resilience more than rapid growth. Many lawn care professionals use zero-phosphorus formulas to comply with local fertilizer ordinances that restrict phosphorus use near waterways. Old Cobblers Farm™ Wicked Growth 6-0-16 Fertilizer delivers lawn-friendly nutrition with environmental responsibility.
What crops benefit from 6-0-16 fertilizer?
Crops that benefit from 6-0-16 include established turfgrass, fruiting vegetables like tomatoes and peppers in phosphorus-rich soils, root crops, berry bushes, and fruit trees that have been receiving phosphorus applications for several years. It is also ideal for hay and pasture fields where phosphorus levels have built up from manure applications. Any crop growing in soil with adequate phosphorus but needing nitrogen and potassium supplementation will respond well to this ratio. Old Cobblers Farm™ Wicked Growth 6-0-16 Fertilizer supports high yields and plant resilience across diverse growing situations.
How much 6-0-16 fertilizer per 1,000 square feet?
For lawns, apply 5–8 pounds of 6-0-16 per 1,000 square feet to deliver approximately 0.3–0.5 pounds of actual nitrogen. For garden beds, use 2–3 pounds per 100 square feet and incorporate into the topsoil. Adjust rates based on soil test results and crop demand. Because 6-0-16 has a lower nitrogen content than many lawn fertilizers, slightly higher application rates may be needed compared to higher-analysis products. Always water thoroughly after application. Old Cobblers Farm™ Wicked Growth 6-0-16 Fertilizer is easy to spread and activates quickly once watered in.
What is the difference between 6-0-16 and 10-10-10 fertilizer?
The main difference is phosphorus content and nutrient balance. 10-10-10 provides equal parts of all three primary nutrients and is best for new plantings, gardens, and soils that need complete nutrition. 6-0-16 contains no phosphorus and emphasizes potassium, making it ideal for established plantings in soils that already test high in phosphorus. Use 10-10-10 when starting a new garden or when soil tests show deficiencies across all three nutrients. Use 6-0-16 for maintenance feeding when phosphorus is adequate. Old Cobblers Farm™ offers both formulas to match your specific soil conditions and crop needs.
Can I use 6-0-16 on fruit trees?
Yes, 6-0-16 works well on established fruit trees, especially those planted in soils with adequate phosphorus. The nitrogen supports canopy growth and leaf health, while the high potassium enhances fruit size, sweetness, flavor, and storage quality. Potassium also improves the tree's ability to handle drought, heat, and cold stress. Apply 1–2 pounds per inch of trunk diameter, broadcast evenly under the drip line. Old Cobblers Farm™ Wicked Growth 6-0-16 Fertilizer is a smart choice for orchards and backyard fruit trees that need potassium-focused nutrition without adding excess phosphorus.
