Skip to Content

How tall do sweet peas grow?

If you are planning on growing sweet peas up a support then you will want to know how tall they can grow. There are a few factors that can influence this, including you the gardener. So let’s have a look and find out how tall sweet peas grow.

Most varieties of sweet peas will grow to 6 feet, but in ideal situations, they can reach 9 or even 10 feet.

Different varieties will grow to different heights, there are dwarf varieties of sweet pea which only grow to around 3 feet, and then there are others that can keep on growing seemingly forever.

Sweet Peas Growing On A Trellis
Sweet Peas Growing On A Trellis

Pruning

How you look after your sweet peas can also affect their final height. A common practice when growing sweet peas is to remove the central growth stem early on in the plant’s life. This encourages the plant to produce more side shoots and grow bushier.

This gives you lots of extra flowers and is an all-around good idea. What it also does though is reduce the final height of your sweet peas as they are putting more energy into growing sideways and also producing more flowers.

Planting

Another factor that can affect how high your sweet peas will grow is when they were planted. If they are planted and the weather isn’t brilliant then the growth of your sweet peas can be stunted. They will tend to grow bushier in colder conditions rather than shooting straight up.

The amount of light your sweet peas get can also affect their height. Sweet peas absolutely love direct sunlight and the more they get the taller they will grow and the more flowers they will produce. this isn’t to say that you cant grow them in partial shade, just that they will always do better in direct sunlight.

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

If you need a way to support your sweet peas why not grow them up a trellis?

Sweetpeas

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?

talking about everlasting sweet peas which do come back every year but do not have the high scent of regular sweet peas.

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.