How to grow sweet peas – from seed, in pots or not for fragrant flowers

Grow sweet peas easily from seed, in a pot or border to enjoy their colorful, scented flowers – perfect for picking and a spectacular garden feature.

How to grow sweet peas
(Image credit: Getty)

All lovers of cottage-style spaces should know how to grow sweet peas. But you don’t have to be a fan of cottagecore, or a pro gardener to enjoy these tiny blooms. Growing sweet peas makes great gardening for beginners and for the naturally green thumbed too. Quick and easy, soon you'll see why the wonderful colors, prolific flowers and beautiful fragrance make them a worthy inclusion in your garden.

Grown up a tepee-shaped support, sweet peas can create an eye-catching vertical feature for a backyard, big or small. They’re also a number one choice if you want to be able to pick flowers from your plot for pretty arrangements inside your home. What’s more, picking the flowers regularly will encourage more to grow... Convinced they’re the blooms for you? We’ve got all you need to know to grow sweet peas if you scroll down. 

What month do you plant sweet peas?

Sweet peas should be planted from mid April. You can sow the seeds from January to April, meanwhile.

Sweet pea seeds can also be sown in fall during the months of October and November but if you take this approach, you’ll need to keep them in a greenhouse or a cold frame over the winter months.

Bear in mind that although you might want to plant sweet peas in a border, they’re also ideal as a feature of kitchen gardens, where they can stand in for a hedge to zone the space and add color and interest. They can also be planted in containers, see below.

Purple sweet peas growing vertically up trellis

(Image credit: Getty Images)

How to grow sweet peas from seed

Method:

1. Choose an appropriate container: sweet peas have long roots, so like a deep pot to grow in. Use root trainers (long thin pots) or even the cardboard inners of loo roll.

2. Use a mixture of seed and multipurpose compost, dampen it, and push one seed per compartment about an inch (2cm) deep.

3. When the plants are around 3 to 4 inches (7.5 to 10cm) in height, pinch out the growing tip (in other words, nip it off using your fingers) to encourage side shoots.

4. You can plant sweet peas out from mid April once there’s no longer a risk of frost. The plants should be hardened off first by putting them outside during the day and keeping them somewhere frost free at night. Plant sweet peas in a sunny spot.

5. Dig compost or well-rotted manure into the area where you’re going to plant the sweet peas. Add general purpose fertilizer to the soil, too.

6. Provide the sweet peas with a structure to grow up; they’re climbing plants. You can make a wigwam shape using bamboo canes or use trellis, an obelisk, or a special sweet pea frame. 

7. Plants should be 2 or 3 inches (5 to 7.5cm) away from the support. Use two plants around 8 to 10 inches apart (20 to 25cm) at the bottom of each upright.

8. Water after planting. 

Tip: If planting after mid-May, you can plant the seeds where they are to flower.

Mixed sweet peas growing in a garden

(Image credit: Getty Images)

How to grow sweet peas in pots

If you have a small garden or like the convenience of pots, you’ll be delighted to hear that sweet peas are ideal for container gardening

The National Sweet Pea Society recommends a minimum container size of 4.5 gallons (20 litres). It should also provide good drainage. 

Use a rich potting compost and add in a loam-based compost that will help retain water, then create a support for the sweet peas to climb up. Tying bamboo canes together is a simple way to do this. 

Put the plants in close to the supports, and water in well. You’ll need to water them every day there’s no rain and once the plants have grown up they may need watering even when it does rain so enough water reaches the soil. You can use a liquid feed regularly to keep the plants in optimum health. 

How do you care for sweet peas?

Sweet peas are fairly easy flowers to grow but they do need some care, but don’t worry this isn’t onerous and they’ll definitely reward your attentions. 

As the plants produce new shoots, they should be tied to the canes, trellis or whatever else you are using to support the sweet peas. You can use special sweet pea support rings or garden twine for the job. The tendrils will naturally grip the supports, but you should keep on tying in as necessary throughout the growing season. 

Make sure plants don’t dry out – you might need to water every three or four days in dry weather for sweet peas planted out in the garden (and see above for advice on watering sweet peas grown in pots).

Once your sweet peas begin to flower, remove dead flower heads frequently and pick the blooms for cut flowers

The cutest addition to any garden!

Anna Cottrell
Anna Cottrell

Anna is Consumer Editor across Future's home brands. She moved to the world of interiors from academic research in the field of English Literature and photography. She is the author of London Writing of the 1930s and has a passion for contemporary home decor and gardening.

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