Potato Seed Rate Calculator
Determine exactly how many pounds of seed potatoes you need for your field or garden.
Acres
Hectares
Square Feet
Square Meters
Calculation Results
Total Plants Needed:
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Net Seed Weight Needed:
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Total Weight (incl. waste):
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Hundredweight (CWT):
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Understanding Potato Seed Rate Calculation
Calculating the correct potato seed rate is crucial for maximizing yield and managing costs. Unlike seeds for corn or wheat, potatoes are planted as "seed pieces" (tubers or cut portions of tubers), which means the weight required per acre is significantly higher than most other crops.
How to Calculate Potato Seed Rate
The amount of seed you need is determined by the population density (how many plants fit in an area) and the size of the individual seed pieces. The standard formula used by agronomists is:
Formula:
1. Total Plants = Area (sq inches) / (Row Spacing × Plant Spacing)
2. Total Weight = Total Plants × Average Seed Weight
1. Total Plants = Area (sq inches) / (Row Spacing × Plant Spacing)
2. Total Weight = Total Plants × Average Seed Weight
Key Variables Explained
- Row Spacing: The distance between the center of one row and the next. Commercial growers typically use 34 to 36 inches.
- In-Row Spacing: The distance between individual seed pieces within the same row. This ranges from 8 inches (for small fingerlings) to 14 inches (for large Russets).
- Seed Piece Weight: The ideal weight for a seed piece is 1.5 to 2.5 ounces. Pieces too small lack the energy to emerge, while pieces too large are an unnecessary expense.
Real-World Example
Scenario: You are planting 1 Acre with 36-inch rows and 12-inch spacing, using 2 oz seed pieces.
- Plant Population: 43,560 sq ft per acre / (3 ft * 1 ft) = 14,520 plants per acre.
- Weight Calculation: 14,520 plants × 2 ounces = 29,040 ounces.
- Conversion to Pounds: 29,040 / 16 = 1,815 lbs of seed.
Why Seed Weight Matters
Seed weight is often the most overlooked variable. If your seed cutter produces pieces that average 2.5 oz instead of 2.0 oz, your seed requirement increases by 25%. For a large-scale farmer, this represents a massive increase in input costs. Using a potato seed rate calculator helps in budget forecasting and ensures you don't run out of seed mid-planting.
Factors That Influence Seed Rate
While the math gives you a baseline, consider these biological factors:
- Variety: Some varieties (like Yukon Gold) perform better with tighter spacing to prevent "hollow heart."
- Target Market: If growing for small "creamer" potatoes, use closer spacing (6-8 inches). For large baking potatoes, use wider spacing (12-14 inches).
- Soil Moisture: Dryland (unirrigated) farming typically requires wider spacing to reduce competition for water.