Why are my potatoes green?

They have been exposed to light, causing chlorophyll and toxic solanine to develop.

Can I grow potatoes in a bag?

Yes, they grow very well in fabric grow bags or deep containers.

Plant guide

Potato.

Solanum tuberosum

Pronounced so-LAY-num too-ber-OH-sum

Also known as Irish Potato, Potato

Potatoes are a staple crop grown for their edible tubers that develop underground. They thrive in cool weather and prefer loose, well draining soil to allow the tubers to expand. You will love harvesting these fresh from your own garden.

Another photo of Potato — Photo by sageost (CC BY) via gbif

At a glance

Care level: Moderate
Plant type: Herbaceous perennial grown as an annual
Light: Full sun
Indoor light: Direct sun
Water: Every 3 to 7 days
Mature size: 3 feet tall
Growth rate: Fast
Hardiness: USDA 2 to 11
Bloom time: Late spring to mid summer

Care

Keep the soil consistently moist but never waterlogged to prevent rot. Hill soil around the base of the stems as they grow to protect developing tubers from sunlight. Watch for yellowing leaves or wilting, which can signal pests or watering issues.

Watering: Keep the soil evenly moist throughout the growing season, especially when tubers are forming.
Feeding: Apply a balanced fertilizer once a month during the active growing phase.
Pruning: Cut back the foliage once it begins to yellow and die down naturally before harvest.
Repotting: Potatoes are typically grown in the ground or large containers and are harvested annually rather than repotted.
Soil: Loamy, well draining soil
Soil pH: 5.0 to 6.0
Temperature: 7 to 27°C
Humidity: 40 to 70%
Drought tolerance: Low
Lifespan: Annual crop, harvested in one season.
Deer and rabbits: Moderate

Signs it needs repotting

Roots growing out of drainage holes.
Plant growth stalling despite regular feeding.
Soil drying out much faster than usual.

Safety

People: The foliage and green tubers are toxic if ingested due to high concentrations of glycoalkaloids.
Pets: The foliage and green tubers are toxic to cats and dogs if ingested.
Children: Keep children away from the green parts of the plant and ensure they do not consume raw tubers.
Contact allergens: Handling the foliage may cause mild skin irritation in sensitive individuals.
Airborne allergens: Pollen from potato flowers is generally not a significant airborne allergen.
Edibility: Never eat green potatoes or any part of the plant foliage, as they contain toxic solanine.

How to identify it

Compound leaves with oval leaflets
Small white, pink, or purple flowers
Starchy edible tubers underground
Hollow or solid green stems

Height: 0.3 to 1m
Spread: 0.3 to 0.6m
Leaves: green, deciduous
Flowers: white, pink, purple, 2 to 4cm
Fruit: brown, yellow, red, purple, Late summer to autumn

Problems to watch for

By symptom

Plant problems by symptom

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Growing it

Propagation: seed potatoes, true botanical seed
When to plant: spring, late summer
Overwintering: In cold climates, harvest all tubers before the first hard frost. In frost free areas, they can be left in the ground until needed.
In containers: Potatoes are excellent for containers, provided you use a pot at least 30 liters in volume with good drainage.

Chitting seed potatoes

1. Place seed potatoes in a cool, bright spot.
2. Wait for short, sturdy sprouts to emerge from the eyes.
3. Plant in soil once sprouts are 2cm long.

Planting aromatic herbs like cilantro nearby can help mask the scent of potatoes from pests.

Grows well with

Bush beans · Beans fix nitrogen in the soil which helps potato growth.
Marigold · Marigolds help deter certain soil dwelling pests.

Keep away from

Tomato · They share similar pests and diseases, increasing the risk of spread.
Sunflower · Sunflowers can inhibit the growth of potatoes through allelopathy.

Similar species

Sweet potato · Often confused due to the name, but they are unrelated species.

Science

Family: Solanaceae
Genus: Solanum
Order: Solanales
Class: Magnoliopsida
Native range: Andes mountains of South America
Conservation: Not of conservation concern as it is a widely cultivated global crop.

It thrives in cool, moist mountain climates where it evolved to store energy in tubers to survive dormant periods.

Value to wildlife: attracts beneficial insects
Pollinators: bees, beetles
Uses: culinary staple, starchy vegetable, container gardening

Through the year

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Flowering

Fruiting

Foliage

Ecological indicators

Salinity: 2/9
Soil reaction: 5/9
Light: 7/9
Temperature: 5/9
Moisture: 6/9
Nutrients: 7/9

Taxonomy resolved against GBIF.

Questions people ask

Why are my potatoes green?: They have been exposed to light, causing chlorophyll and toxic solanine to develop.
Can I grow potatoes in a bag?: Yes, they grow very well in fabric grow bags or deep containers.

Where the name comes from

The name Solanum comes from the Latin word for soothing, while tuberosum refers to the tuberous nature of the plant.

Good to know

Potatoes belong to the nightshade family along with tomatoes and peppers.
There are over 4,000 edible varieties of potatoes worldwide.
Potatoes are technically modified underground stems called tubers.

Also in

Plants toxic to cats and dogs

Keep your potato growing

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This guide was generated with AI on September 26, 2026 and checked against GBIF taxonomy. It is general information, not horticultural or veterinary advice. Read about how we build these guides.