How to Grow Sweet Pea
Sweet Pea At a Glance
Difficulty
Easy
Category
Flower
Sun Exposure
Full Sun
Frost Tolerance
Frost Hardy
Cold Hardiness
Survives to -7°C
Plant Family
Fabaceae
Growing Season
Cool Season
Plant Lifecycle
Annual
How to Start It
★ Recommended for beginners
Sweet peas love cool weather and shrug off light frost, so sow them as soon as the soil can be worked, about 4 weeks before your last spring frost. Soak the seeds overnight, then sow them 2 cm deep and 15 cm apart along a fence, net or trellis. They sprout in 10 to 21 days. When the seedlings are about 10 cm tall, pinch off the tip so they branch and give more flowers.
Sweet peas are climbing flowers with a famous sweet scent, and the more you pick, the more they bloom. They flower best before summer gets hot, so an early start matters more than anything. Sweet peas are for looking at and smelling only: unlike garden peas, they are not edible.
When To Start
Sweet Pea likes cool weather. Sow it in early spring, as soon as the ground can be worked.
We do not have exact sowing dates for this one yet.
When should you plant Sweet Pea?
Your planting dates depend on your local climate. Sign up and add your location to unlock personalized dates.
Your Sweet Pea Planting Window
Start planting
May 15, 2026
Last chance
Sep 10, 2026
Your Sweet Pea Calendar
Set your location to turn these into exact dates and reminders.
Sow sweet peas outdoors now along a support
4 weeks before your last frost· every year
Optional: start sweet peas indoors in deep pots
8 weeks before your last frost· every year· optional
Plant indoor sweet peas out against a support
Around your last frost· every year· optional
Cut sweet peas every 2 to 3 days and snip off pods
60 days after your last frost· every year· optional
Did you water your sweet pea seedlings today? Keep the top of the soil damp until they are up and growing.
About 1 days after you plant it
How are your sweet peas? Guide the young vines onto their support so they can climb.
About 30 days after you plant it
Checking in on your sweet peas. Cut the flowers every few days or the plant stops blooming.
About 90 days after you plant it
The Journey Ahead
Sweet Pea's Lifecycle
Seedling
Mature Plant
Seed Production
Step 1
Prepare Your Space
2 cm
Seeding Depth
15 cm
Plant Spacing
30 cm
Row Spacing
Vertical Growing
No.
Succession Planting
Yes: successional autumn + spring sowings extend the season.
Good Companions
Bad Companions
Step 2
Planting & Sprouting
Expect sprouts in 10–21 days
Growing Tips
- 1Plant sweet peas in full sun, with their roots shaded by low plants or mulch.
- 2Dig plenty of compost into deep, rich soil before sowing.
- 3Water deeply about twice a week in warm weather, since dry roots make the buds drop and bring on mildew.
- 4Feed with compost tea every 2 weeks once flowering starts.
- 5Give them a fence, net or trellis about 2 m tall, and tie the young shoots in until their curly tendrils take hold.
- 6The seeds and pods are toxic to people and pets, so keep them away from children and animals.
Seedling Phase
Step 3
Growth & Maturity
180 cm
Mature Height
25 cm
Mature Width
Pests to Watch For
Diseases to Watch For
Mature Plant
Step 4
Harvesting
When to Pick
Blooms late spring through summer; cut every few days or it stops flowering
How to Harvest
- 1Cut flowers in the morning when the lowest flower on a stem is fully open.
- 2Pick every 2 to 3 days, because a plant that sets seed pods soon stops flowering.
- 3Snip off any pods you missed as soon as you see them.
- 4Cut long stems and put them straight into water, where they last a few days.
- 5Pull the plants when hot weather stops the flowers, and add them to the compost.
Step 5
Saving Seeds
How to Save Seeds
Sweet pea flowers mostly pollinate themselves before they open, so seeds of a variety that is not a hybrid come fairly true (hybrid F1 seeds will not). Late in the season, stop picking a few of your best plants and let their pods ripen. Pick the pods when they turn brown and papery, before they twist open and throw their seeds. Shell out the round seeds and dry them for a week. Store them labelled as not edible, in a cool, dark, dry place, where they keep about 3 years.
Seed Production
Still have a question?
Ask your coach about your sweet pea.
This page covers what we thought to write down. Your sweet pea will do something it never mentions, and that is the day a coach beats a guide. Ask Coach Lumen one question right now, free, no account.
