Are Sweet Peas Safe for Humans? Separating Myth from Fact

December 25, 2025 •

3 min read

Despite their appealing name and beautiful, fragrant flowers, ornamental sweet peas are not safe for human consumption. All parts of the ornamental sweet pea plant (Lathyrus odoratus), especially the seeds, are toxic to humans and animals. The confusion often arises because they are not the same as the edible green peas (Pisum sativum) found in vegetable gardens and grocery stores.

Quick Summary

Ornamental sweet pea plants are poisonous to humans and pets, with the seeds containing neurotoxins that can cause lathyrism if consumed in large quantities. They must not be confused with edible garden peas. Knowing the differences between the two is crucial for home gardeners to ensure safety.

Key Points

Ornamental sweet peas are toxic: The seeds of Lathyrus odoratus contain a neurotoxin that can cause paralysis if ingested in large amounts.
Edible peas are a different plant: Garden peas (Pisum sativum) are a completely separate species from ornamental sweet peas.
Check plant names carefully: Always verify the botanical name of a pea plant before harvesting or consuming any part of it.
Look for winged stems on toxic plants: Ornamental sweet peas have distinctly winged or flattened stems, unlike the round stems of edible peas.
Supervise children and pets: Keep ornamental sweet peas away from young children and pets who might be tempted to eat the seeds or pods.
Remove mature pods from ornamental varieties: To reduce the risk of accidental ingestion, regularly deadhead flowers and remove any maturing seed pods from ornamental sweet pea plants.

Understanding the Toxicity of Sweet Peas

The most common sweet pea grown in gardens is Lathyrus odoratus, a member of the Fabaceae family. It is cherished for its vivid, colorful blossoms and pleasant aroma, not for its edibility. The seeds of this ornamental plant contain a neurotoxin, beta-aminopropionitrile (BAPN), which can cause a condition known as lathyrism if ingested in significant quantities over an extended period. Lathyrism can lead to neurological and skeletal abnormalities, with symptoms including paralysis, muscle weakness, and other severe health issues. While small, accidental ingestions may not cause immediate poisoning, any amount should be treated seriously, especially concerning children and pets.

The Critical Difference Between Ornamental and Edible Peas

The fundamental source of confusion lies in the name. Edible garden peas, including shelling peas, snap peas, and snow peas, belong to the Pisum genus, specifically Pisum sativum, a completely different species from the ornamental sweet pea. Distinguishing between these two plants is essential for any home gardener.

Ornamental Sweet Pea (Lathyrus odoratus): Grown for its flowers. Seeds are toxic. Winged and rough stems.
Edible Garden Pea (Pisum sativum): Grown for edible pods and seeds. Round and succulent stems.

Key Identification Features

To prevent accidental poisoning, it is important to be able to identify the non-edible sweet pea clearly. Here are some distinguishing features:

Stem: Ornamental sweet peas have noticeably winged, or slightly flattened, rough stems. Edible peas have round, smooth stems.
Flowers: Sweet peas are cultivated for their large, fragrant, and showy flowers, which can be pink, purple, white, or various bi-colors. Edible peas have smaller, less conspicuous flowers that are often white.
Pods and Seeds: The pods of ornamental sweet peas mature into dry capsules containing the toxic seeds. They should not be mistaken for edible pea pods.

Symptoms of Lathyrism and Sweet Pea Poisoning

While human poisonings from garden-grown sweet peas are rare in Western countries due to their typically non-staple status, severe cases from large-quantity consumption have been documented historically in other parts of the world. Symptoms can be delayed and may include:

Muscle weakness and paralysis
Slow and weak pulse
Breathing difficulties
Convulsions
Lethargy
Tremors

How to Safely Garden and Cultivate Peas

For gardeners, enjoying the fragrant beauty of ornamental sweet peas and the delicious taste of edible peas requires careful planning and awareness. Here is a brief guide to safe gardening practices:

Segregate Planting Areas: Keep ornamental sweet peas and edible pea plants in separate, clearly marked garden beds to avoid any confusion during harvest. This is especially important if you garden with children.
Proper Labeling: Use clear labels for all plants. For ornamental sweet peas, labels should indicate the non-edible nature of the plant and its seeds.
Educational Awareness: Teach all members of your household, particularly children, the difference between the two plants and explain why one is not safe to eat.
Remove Seed Pods: To prevent accidental reseeding and to encourage more flowering, regularly deadhead ornamental sweet pea flowers before they can form mature seed pods.


Feature	Ornamental Sweet Pea (Lathyrus odoratus)	Edible Garden Pea (Pisum sativum)
Toxicity	All parts are toxic, especially seeds.	Edible. Shoots, pods, and seeds are safe.
Stems	Winged, flattened, and rough textured.	Round, hollow, and smooth textured.
Flowers	Large, very fragrant, showy flowers in many colors.	Smaller, less prominent, typically white flowers.
Usage	Ornamental, cut flowers.	Culinary, vegetable consumption.
Warning	Do not consume any part. Keep away from children and pets.	Safe for consumption when prepared correctly.

Conclusion

In summary, the beautiful and sweet-scented ornamental sweet pea (Lathyrus odoratus) is not safe for human consumption, especially the seeds, due to the presence of neurotoxins. The risk of poisoning (lathyrism) is directly linked to prolonged, high-quantity ingestion, but caution is always warranted. In contrast, the edible garden pea (Pisum sativum), which includes shelling, snap, and snow peas, is perfectly safe to eat. By understanding the distinct differences between these two plants and practicing responsible gardening, you can safely enjoy both the stunning fragrance of one and the delicious flavor of the other. For more on the botany of poisonous plants, consult reliable sources like the International Veterinary Information Service (IVIS).

Frequently Asked Questions

While it is true that severe poisoning (lathyrism) is typically linked to long-term, high-quantity consumption, any ingestion of the seeds is considered a risk. Toxin levels can vary, and it is best to avoid consuming any part of the ornamental sweet pea (Lathyrus odoratus) to prevent potential health issues.

The flowers of Lathyrus odoratus are sometimes used as a garnish in small quantities, but even this is debated. The seeds are the most toxic part of the plant and should never be consumed.

Lathyrism is a neurological disease caused by eating large amounts of certain Lathyrus species seeds over time. It can cause muscle weakness, paralysis, and skeletal deformities.

The primary difference lies in the species: sweet peas are Lathyrus odoratus, while edible peas are Pisum sativum. Visually, look at the stems; ornamental sweet peas have flattened, winged stems, whereas edible peas have round stems.

Yes, many species within the Lathyrus genus, including the perennial or everlasting pea (L. latifolius), contain similar toxins and should be treated as poisonous.

Yes, pets can also be poisoned by ingesting ornamental sweet pea plants. The symptoms in animals are similar to those in humans, and the risk of poisoning is especially relevant for larger animals like horses that might graze on the plant.

If you suspect that a person, child, or pet has ingested any part of an ornamental sweet pea plant, it is crucial to contact a poison control center or seek medical attention immediately.