If you have just planted up some young sweet peas you will no doubt be eager to know just how soon they will be flowering. Well, let’s have a look and find out when sweet peas flower so you know exactly when you can expect those first buds to start appearing.
How long do sweet peas take to flower?
As a general rule of thumb sweet peas will start to flower after around 3 months of growing. So if you sowed a seed in early march you could expect it to start flowering around June.
Obviously, there are so many factors that go into this that it is impossible to give an exact timeframe but this rough estimate should serve you well. This 3-month guide does not hold true for autumn-sown sweet peas as they will de more dormant and slow-growing over winter.
When do sweet peas flower
The usual flowering months for sweet peas are June all the way through to October depending on when they were sown. This season can be extended or shortened at either end depending on where you are in the country and what the weather does in that individual year.
The main flowering season and when you will get your best displays tend to be June and July. This will depend on when you started growing the sweet peas but this is when most plants are at their best. You can regularly deadhead the old flowers to make the plant produce new flowers and extend its flowering period.
My sweet peas aren’t flowering, what could be wrong?
The most common cause for sweet peas not flowering or not flowering well is that they simply aren’t getting enough sun. Sweet peas like full sun and the more full sun they get the more flowers they put on.
If your sweet peas are in a particularly shady spot then they may not flower well at all. if possible try and move them into a sunny spot. If they are in pots you can do this for a couple of hours a day before putting them back in their original position.
For more help and advice on non flowering sweet peas check out my full guide.

More on 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?
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.