How to Care for Lathyrus odoratus (Sweet pea)

Korean name: 스위트피

A climbing annual with butterfly-shaped, sweetly scented flowers. It climbs supports with its tendrils and blooms best in a cool spring. The flowers look like garden peas, but the seeds and pods are poisonous and must not be eaten.

Key facts

Care Guide

Detailed care guide

Sweet pea is a climbing annual with sweetly scented, butterfly-shaped flowers. It blooms best in a cool spring and needs something to climb.

Watering

Water thoroughly when the topsoil is dry. Once buds form, running short of water makes them drop. Soggy roots rot, though, so make sure it drains well.

Light

It needs direct sun — six or more hours a day for a good show of flowers.

Humidity

Normal humidity is fine. Poor airflow makes powdery mildew likely.

Temperature

It likes cool weather at 10–20°C. Above 25°C the flowers fade quickly and the plant starts to decline.

A common first-timer mistake

Cut the flowers often for a vase and it makes more. Pick off pods as soon as they form, since setting seed reduces flowering.

If you have pets

Sweet pea seeds and pods are poisonous to people and pets. Don't confuse them with garden peas.

Through the Seasons

In Korea, sow in autumn (October–November) to overwinter, or in early spring (February–March). Soaking the seeds overnight helps them sprout. When the vines start to run in spring, put up a support or net, and once buds appear feed a high-phosphorus fertiliser every two weeks. It finishes when early-summer heat arrives.

Common Problems and Fixes

A white powder on the leaves is powdery mildew; remove affected leaves and improve airflow between plants. Dropping buds point to a lack of water or a sudden heat spell. Aphids like the new shoots, so check them often.

Repotting and Propagation

Its roots go deep, so start it in a deep pot or in the ground and avoid transplanting. It is grown from seed. Collected seeds are toxic, so store them out of children's reach.

Who It's Good For

It's a great pick for anyone who wants to grow fragrant flowers for the vase. You'll want room for the vines to climb and a sunny balcony or garden.

Written by AI from the care facts in this entry. Treat it as a starting point.

Common questions

How often should you water Lathyrus odoratus?

Water thoroughly when the topsoil is dry. If it runs short of water while flowering, the buds drop. Roughly every 3 days is the baseline; adjust for the season and the spot it sits in.

Where should you keep Lathyrus odoratus?

It likes Direct sun. It needs six or more hours of sun a day.. You can grow it outdoors. Use Deep, fertile, well-draining soil.

Is Lathyrus odoratus safe around pets?

Toxic, so keep it well away from pets and children.

Is Lathyrus odoratus good for beginners?

Difficulty: Moderate. Keep it around 10–20°C. It likes cool weather and stops flowering quickly above 25°C.. Humidity: Normal humidity. Poor airflow brings powdery mildew.. Fertilise High-phosphorus liquid feed every 2 weeks once buds form.