Why do Potatoes Grow Underground?

Hello again, fellow gardeners!  I’ve often been emailed a question by one of my lovely readers (Alex from Sheffield) about potatoes – ‘why do potatoes grow underground?’ It’s a fascinating aspect of these versatile and nutritious tubers that deserves some exploration. So, let’s delve into the world of potatoes and discover the reasons behind their subterranean growth habit.

Potatoes are tubers, not roots

First and foremost, it’s essential to understand that potatoes are tubers, not roots. A tuber is a specialised part of the plant’s stem that grows underground and functions as a storage organ. Tubers like potatoes store nutrients and energy, allowing the plant to survive through periods of dormancy or unfavourable growing conditions.

By growing underground, potatoes can effectively fulfil this role, remaining protected from environmental factors and predators. Its a clever adaptation.

Protection from sunlight

Exposure to sunlight can cause potatoes to produce chlorophyll, turning them green and increasing the levels of a toxic compound called solanine. By growing underground, potatoes are shielded from direct sunlight, reducing the risk of solanine production and keeping them safe for consumption.

Safe from pests and predators

Growing underground also helps protect potatoes from various pests and predators that may damage or consume them. Although some pests, such as wireworms and voles, can still attack potatoes underground, the risk is significantly reduced compared to if they were growing above ground.

This protection is vital for the plant’s survival and the eventual production of new plants from the tubers.  Though pests can eat the leaves once the potatoes plant starts producing foliage – as we have previously written about.

Conservation of water and nutrients

As potatoes develop underground, they can maintain consistent moisture levels and access a steady supply of nutrients. The soil provides a stable environment that helps preserve water and nutrient reserves, ensuring that the potato plant can continue to grow and produce tubers even during periods of drought or other adverse conditions.

Facilitates vegetative reproduction

Potatoes reproduce vegetatively, meaning new plants can grow from the tubers themselves. Each potato tuber contains multiple “eyes” or buds, which can sprout and develop into new plants. Growing underground allows these buds to easily take root and access the necessary nutrients and moisture to grow into healthy plants, ensuring the continuation of the potato’s life cycle.


In conclusion, potatoes grow underground because it provides them with several advantages that contribute to their growth, reproduction, and survival. The subterranean environment shields potatoes from sunlight, pests, and predators while also conserving water and nutrients.

These factors combine to create the ideal conditions for potato tubers to thrive, making them the delicious and versatile crop that we all know and love.