Best Fertilizer for Potatoes
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GardenSays
Work about 0.5 lb of balanced garden fertilizer (e.g., 10-10-10) into your 32 sq ft bed before planting.
- Fertilizer
- 10-10-10
- Amount
- ≈ 0.5 lb
- Next feeding
- At first fruit
For a 32 sq ft bed, that's roughly 0.5 lb (8 oz) of fertilizer, spread evenly and worked into the top 6 inches a few days before planting. A soil test beats any rule of thumb — if you have one, follow it instead.
- Don't lime the potato bed — scab worsens as pH rises; potatoes prefer slightly acidic soil.
- Heavy nitrogen means big vines and late, small tubers.
Do this this week
- 1.Spread ≈ 0.5 lb of balanced fertilizer (e.g. 10-10-10) evenly over the 32 sq ft bed
- 2.Work it into the top 6 inches a few days before planting
- 3.Then hold — nothing more until when shoots are about 6 inches tall, at first hilling
Typical estimate · 1 verified source · Checked 2026-07-16 · How we decide
Why
Then hold off: no more fertilizer until when shoots are about 6 inches tall, at first hilling. Feeding again too early is the classic way to get a huge green plant with no fruit.
- One balanced pre-plant application plus a fruit-set sidedress matches how demand actually rises.
- A moderate feeder with a catch: excess nitrogen grows lush vines and delays tuber set, and over-limed beds invite scab.
When this doesn't apply
- Soil test results override this: high-P soils need nitrogen-only products.
- Beds heavily amended with compost each year may need only half this rate.
How this was calculated
- 1. Feeding profile
Potato: A moderate feeder with a catch: excess nitrogen grows lush vines and delays tuber set, and over-limed beds invite scab.
- 2. Pre-plant rate1.5 lb/100 sq ft (our estimate)GardenSays estimate
balanced garden fertilizer (e.g., 10-10-10): 1.5 lb per 100 sq ft (midpoint of published extension rates), worked into the top 6 inches
- 3. Your bed≈ 0.5 lb (8 oz)Calculated result
1.5 lb/100 sq ft × 32 sq ft
Data sources
- University of Minnesota Extension — Growing potatoes in home gardens — Feed moderately and sidedress at hilling; excess nitrogen delays tuber development and high pH increases scab. (checked 2026-07-16)
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People also ask
When should I fertilize potatoes?
Work about 0.5 lb of balanced garden fertilizer (e.g., 10-10-10) into your 32 sq ft bed before planting. Calculate yours →
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