Why Are My Potatoes Small? Causes and Fixes

Why potato tubers stay small or few: harvesting too early, drought at tuber formation, poor soil, too much nitrogen, crowding, heat, disease and pests.

Muhammet Elma 3 November 2026 2 min read

Small potatoes usually come from harvesting too early, drought when tubers are forming, or plants that died back early from blight, heat or pests. Too much nitrogen gives lush leaves but few tubers.

Common Causes

Early harvest: new potatoes are small by nature.
Uneven watering: dry spells around flowering limit tuber growth; irregular watering causes cracks and hollow heart.
Heat: tuber growth slows above about 27 °C (80 °F).
Too much nitrogen: leaves instead of tubers.
Low potassium or compacted soil.
Crowding: plants closer than 25–30 cm.
Early die-back: late blight, early blight or Colorado potato beetle.
Poor seed: virus-infected tubers.

How to Grow Bigger Potatoes

Plant certified seed at the right spacing.
Hill regularly and mulch to keep soil cool.
Water 2.5–5 cm (1–2 in) a week from flowering on.
Use a balanced fertilizer with plenty of potassium.
Protect foliage from blight and beetles.

More Potato Guides

Frequently Asked Questions

Why do my potato plants have lots of leaves but few potatoes?

Usually too much nitrogen or not enough sunlight.

Do flowers mean potatoes are ready?

Flowers signal that tubers have started forming and new potatoes can be dug.

Muhammet Elma

TarlaTapan guides focus on practical, field-tested growing advice. Corrections and suggestions are welcome at info@tarlatapan.tr.