Flower Focus: Sweet Peas
Sweet peas are such a sweet flower (pun intended). They have delicate, ruffled petals and smell wonderful. They’re the perfect flower for your spring and early summer gardening.
Sweet peas symbolize many things, but are most often associated with friendship and loyalty.
Today we’re going over the basics of sweet peas, along with how to plant and harvest them.
The Basics
Zone: 3-8
Bloom time: Early spring to early summer
Needs: Full sun and well-draining soil
Size: 6-8’ tall
What They Look Like
Their colors range from soft pastels to vibrant jewel tones. They’re climbing plants, so here at Sweet Earth Co. we grow them on vertical trellises and love watching them climb the supports and offer the season’s first armfuls of blooms!
How to Sow Sweet Peas
Sweet peas are best started early—either indoors in late winter or early spring or directly in the garden as soon as the soil can be worked. We sow ours in trays right around St. Patrick’s Day, and then again directly into the garden a few weeks later. Here’s how to get a jump on the season:
What You’ll Need
Sweet pea seeds
Deep pots or root trainers (sweet peas prefer long root runs)
Seed-starting mix
Trellis or netting for support
Tray and humidity dome (optional)
Step-by-Step
Soak Your Seeds
Soak sweet pea seeds in water overnight (8-12 hours) to soften their hard seed coats and encourage germination.Prepare Your Containers
Fill deep pots or root trainers with seed-starting mix. Press the mix down gently to eliminate air pockets.Plant the Seeds
Sow 1-2 seeds per cell, about 1 inch deep. Cover lightly with soil and water in.Provide Warm Temps then Light
Place the seed trays on a heat mat or in a warm location; sweet pea seeds require temperatures around 65-75°F to germinate. Once they have germinated, move them off the heat mats and place them under grow lights. Keep them within 2” or so from the lights so they don’t get leggy.Pinch for Bushier Plants
Once seedlings have two sets of true leaves, pinch out the top set to encourage branching and more flower stems.Harden Off Before Transplanting
About 1-2 weeks before your last frost, begin hardening off your seedlings by gradually exposing them to outdoor conditions.Plant Out
Transplant seedlings 6” apart near a trellis or support system. Water well and mulch to retain moisture. You use a root booster, like Myco+, to support better root mass.
Want to see the step-by-step? Check out our YouTube video all about sowing sweet peas.
Encouraging Blooms
Sweet peas are day-length and temperature sensitive. They thrive in cool weather and often sulk in the heat. To encourage lush blooms:
Keep picking! The more you harvest, the more they flower. Allowing pods to develop will signal the plant to stop producing.
Feed lightly. Use a balanced organic fertilizer or compost tea early in the season to support growth.
Mulch and water consistently. Sweet peas have shallow roots and benefit from regular moisture and cool soil.
Succession Planting Tips
Sweet peas are typically spring bloomers, but you can extend your harvest window with a bit of planning:
Fall sowing (in mild climates): Sow in late fall for earlier blooms in spring.
Staggered spring plantings: Start a second round of seeds 2-3 weeks after your first sowing for a longer bloom period.
Choose early, mid, and late-season varieties to naturally stagger flowering.
Just remember—they don’t like the heat. Once summer arrives in full force, they’ll begin to decline, but you can get a solid 6-8 week run of blooms with good planning.
Harvesting Sweet Peas
Harvest sweet peas in the morning when the blooms are fresh and well-hydrated.
Pick when 2-3 flowers are open on the stem for best vase life.
Use clean, sharp snips and cut stems at a 45° angle.
Condition in cool water for at least an hour before arranging.
Regular harvesting encourages continued flowering and prevents the plant from going to seed prematurely.
Saving Seeds
Saving sweet pea seeds is pretty simple—just be aware that saved seeds will only breed true if grown from open-pollinated (non-hybrid) varieties. Here’s how to do it:
Allow pods to mature fully on the plant. They will dry and become papery.
Harvest pods before they split open. You’ll hear a rattle when they’re ready.
Dry seeds indoors for a few days, then store them in a cool, dark place in a labeled envelope or jar.
Pro tip: Keep your seed-saving plants separate from others to minimize cross-pollination if you grow multiple varieties.
Arranging Sweet Peas
Sweet peas shine in arrangements all on their own or paired with other spring stars like ranunculus, anemones, tulips, and garden roses. Their delicate stems and tendrils add a whimsical, airy element to bouquets.
Vase life is generally 4-6 days.
Strip the lower leaves to prevent rot in water.
Refresh the water daily to prolong their life.
