Spreader Settings for 10-20-20 Fertilizer on a New Lawn

The Problem

Scotts spreader settings are calibrated for high-nitrogen products (e.g., 29-3-4). Your 10-20-20 has only ⅓ the nitrogen concentration, so you must open the spreader much wider.

Calibration Method

1. Target rate: 10 lbs of 10-20-20 per 1,000 sq ft (delivers 1 lb N/1,000 sq ft).
2. Calculate total needed: Lawn area (sq ft) ÷ 1,000 × 10 = lbs required.
3. Test run: Fill spreader with a known weight (e.g., ½ bag). Set to medium-high. Run once over a measured section. Weigh remaining product. Adjust setting until application rate matches target.

Example

5,000 sq ft lawn → 50 lbs needed. If 75-lb bag, use ⅔ bag. After one pass, if 25 lbs used, make a second pass at same setting.

Cross-Hatch Pattern

Apply at half rate in two perpendicular directions (N-S then E-W) for uniform coverage.