When to plant sweet peas

Sharing is caring!

Who doesn’t love sweet peas? But in order to get the best possible display you need to make sure you plant them at the right time, but, when is the right time to plant sweet peas? Let’s have a look!

When to sow sweet peas

The most common time to sow sweet peas in the UK is in spring. They can be sown indoors or in a heated greenhouse from March.

From April/may depending on where in the country you are you can sow sweet peas outside.

When to plant out sweet peas

You can plant out sweet peas as soon as the risk of frost has passed. Realistically you are probably looking at may before it will be safe enough to plant out your sweet peas. Again this can change though depending on whereabouts in the UK you actually are.

For me here in Northern England, we can still get frosts quite regularly in April so I wouldn’t want to risk moving sweet peas into the garden too early.

You will also want to harden off any sweet peas you have sown indoors. You can easily do this by moving them outside during the day and bringing them back indoors at night. You then want to gradually lengthen the amount of time you leave the young plants outdoors.

Overwintering sweet peas

A common method for growing sweet peas is to actually sow them in autumn and then overwinter the young plants. You just need to make sure you have somewhere where you can grow the plants that will remain frost-free.

You don’t however want to grow them indoors as they will put on too much growth and need to be moved outside when the conditions are still way too cold.

If you do over winter your sweet peas though you will end up with a really strong and healthy plant that is just raring to get going in spring. I would also recommend doing a spring sowing of sweet peas to go along with your autumn sowing. This will help extend the flowering period of your sweet peas massivley.

Mixed colours of sweet pea flowers
Mixed colours of sweet pea flowers


sweet peas, (Lathyrus odoratus) are a flowering plant belonging to the legume family. They are an annual flower that loves to climb and spread, in the right conditions and with the correct support they can grow to 2 and a half meters tall!

Unlike many other legumes which are grown to be eaten, sweet peas are grown for purely aesthetic reasons. There is evidence to suggest that the pea seeds from a sweet pea plant are actually toxic to humans and not fit for consumption even if this was desired.

Sweetpea FAQ’s

Are sweet peas perennial?

No sweet peas are an annual plant, they will not come back year after year.

Can you eat sweetpeas?

No, sweet peas are grown purely for their looks. Unlike many other legumes, they are actually toxic to humans if consumed.

Are sweet peas poisonous to pets?

Yes, as they are poisonous to humans they are also poisonous to pets, so make sure you keep an eye on your pets when they are hovering around sweet peas.

How high can sweet peas grow?

With the proper support, sweet peas can grow to 2m or even slightly above!

When do you grow sweet peas?

The traditional season for sweet peas is June and July but with the right care and attention, they can be both started earlier and grown later into the season. Regular deadheading of sweetpeas can massively prolong their flowering period.

How to germinate sweet peas?

I like to soak my sweet pea seeds in water for 24 hours before planting them in a seed tray. This soaking helps to break down the tough shell around the seed allowing them to germinate better.

Sharing is caring!

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *