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How to Grow Sweet Peas

Imagine your garden filled with the fragrance of sweet peas—delicate flowers that evoke memories and add a touch of nostalgic charm. Sweet peas are relatively easy to grow and bring beauty, fragrance, and character to any garden. Learn how to grow sweet peas with the tips in this article.

My first encounter with sweet peas was at The Butchart Gardens in British Columbia, and I was captivated by their beauty. But their sweet fragrance won me over when I grew them in my garden. Many people have told me that sweet peas remind them of their mom’s or grandma’s garden—a heartwarming connection to past generations.

Article Index

1. Timing is Key: Plant Sweet Peas Early in the Season
2. Pick the Perfect Sweet Pea Variety for Your Garden
3. How to Properly Plant and Care for Sweet Peas
4. Support Your Sweet Peas as They Grow
5. Maximize Blooms with These Sweet Pea Growing Tips

Harvesting Tips for Cut Flowers

1. Timing is Key: Plant Sweet Peas Early in the Season

The best time to plant sweet peas depends on your climate, but in general, they can be directly sown into the ground in early spring or fall, when soil temperatures range from 50-60°F (10-15°C). These cool-weather lovers thrive before the heat sets in.

• Cooler Climates (Zones 7 and below): Start seeds indoors and transplant them outdoors as soon as the soil is workable. Don’t wait for the last frost.
• Mild Winter Areas (Zones 8-10, like Arizona’s low desert): You can plant outdoors between October and February.

Seed Starting Schedule for Arizona’s Low Desert:

• Start seeds indoors: September – January.
• Plant seeds or transplants outdoors: October – February.

If you wait to plant until the end of the planting window, choose an area that gets less sun. They will have the best chance to produce blooms before it gets hot.

2. Pick the Perfect Sweet Pea Variety for Your Garden

Not all sweet peas are the same; choosing the right variety for your climate is important. Some varieties are sensitive to day length, and the fragrance levels vary. Here’s a guide to help you select the perfect sweet pea:

• For Mild Summer Areas: ‘Saltwater Taffy Swirls,’ ‘Spencer Mix’
• For Hot Summer Areas: ‘Perfume Delight,’ ‘Jewels of Albion’
• For Most Climates: ‘Chiffon Elegance,’ ‘Velvet Elegance’
• Shorter Variety (Great for Containers): ‘Knee-Hi ’ ‘Windowbox’

Read this article for an in-depth guide to choosing the best sweet pea varieties for your climate and preferences.

Poppies are an excellent companion flower for sweet peas. Learn how to grow poppies in this guide.

3. How to Properly Plant and Care for Sweet Peas

Sunlight:

Pick a location with at least 6 hours of sunlight a day. In hot climates like Arizona, morning sun with afternoon shade will prolong blooming longer into spring.

Soil Preparation:

Sweet peas need well-drained soil. Amend the soil with compost and organic matter before planting.

Planting:

• Sow seeds 1 inch (2.5 cm) deep and space them 2-3 inches (5-7.5 cm) apart.
• Thin seedlings to about 5 inches (12.5 cm) apart once they reach 2-3 inches (5-7.5 cm) tall.
• For square-foot gardening, plant 4 sweet peas per square.

Care:

• Mulching: Mulch around the base of your plants to retain moisture and suppress weeds.
• Watering & Fertilizing: Water regularly and deeply, and feed your plants every few weeks with a balanced fertilizer to promote healthy growth and abundant blooms.
• Pest Management: Watch for common pests like aphids and slugs. Powdery mildew can also be an issue, so monitor your plants closely.

Pruning Tips:

• Pinch Back: When the plants have 4-6 leaves, pinch off the top 1-2 inches of growth to encourage bushy plants and more flowers.
• Deadheading & Trimming: Regularly remove spent flowers to encourage more blooms. Cut back plants by half after the first flush of blooms if temperatures are still cool to promote new growth.

4. Support Your Sweet Peas as They Grow

Sweet peas are climbers, and most varieties will reach heights of 8-10 feet. Install sturdy supports like trellises before planting to avoid disturbing their roots later. Guide young plants to the support structure, and they will naturally climb.

Support Options:

• Trellis: Buy one or create your own using wood or bamboo stakes.
• Arches: Train your sweet peas to climb over metal or wooden arches.
• Fences: If you have a fence, let your sweet peas climb up it for an easy support system.
• Obelisks: These tall, narrow structures are ideal for vertical growing.
• Hanging Baskets: For a different approach, grow shorter sweet peas (like Knee-Hi or Windowbox) in hanging baskets, letting the vines trail over the sides.

5. Maximize Blooms with These Sweet Pea Growing Tips

To keep your sweet peas blooming beautifully throughout the season, follow these tips:

• Deadhead Regularly: Remove fading blooms to encourage new flowers. Flowers left on the plant quickly develop into seeds. This causes flower production to slow down.
• Consistent Watering: Sweet peas prefer moist but well-draining soil. Keep the soil hydrated, especially during dry spells.
• Fertilize: Feed your plants every 3-4 weeks with a fruit and flower fertilizer to keep the blooms coming.
• Keep Them Cool: In hot climates, mulch around the base to keep the roots cool and retain moisture.
• Provide Support: As the plants grow, ensuring strong support prevents tangling and encourages more blooms.

Harvesting Tips for Cut Flowers

Once your sweet peas begin blooming, harvest them frequently to encourage continued flowering. Here’s how to get the best from your cut flowers:

• Don’t let seed pods form if you want more blooms. However, if you wish to save seeds, be aware that hybrids may not grow true to type.
• Harvest flowers in the morning for the longest vase life.
• Pick blooms when all but the top few flowers have opened, as they won’t open further once cut.
• Immediately place stems in water to preserve freshness.
• Sweet pea blooms typically last 5-7 days. Adding sugar or a floral preservative can extend their vase life.

Sweet peas are a joy to grow, offering beauty and fragrance to your garden. You’ll be rewarded with a spectacular display of blooms with the right care and conditions. Have questions about growing sweet peas? Leave a comment below.

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