How to Grow and Care for Sweet Pea Flowers

Growing sweet peas is easy and rewarding. These lovely climbing annual flowers bring color and fragrance to any garden. There’s a lovely array of hues to pick from as well, from soft pastels to vivid jewel tones. In this article, we’ll explore everything you need to know to grow and care for sweet peas successfully, from planting tips to ensuring your blooms thrive throughout the season.

Growing from Seed vs Transplanting

Sweet peas can be grown from seeds or transplants. Both methods have their pros and cons.

Growing from seed is cheaper and gives you more variety. You can start seeds indoors 8-10 weeks before the last frost. This gives plants a head start. Or you can sow them directly in the garden about 6 weeks before the last frost.

Transplants save time and effort. They’re already growing, so you’ll see flowers sooner. But they can be pricey, and you’ll typically have fewer choices.

Both methods work great. Seeds are fun if you like to watch things grow from scratch, and transplants are perfect if you want quick results. Pick what suits your style and schedule best!

How to Plant

Setting sweet peas up for success is key for optimal flowering each season. The right location, timing, and method can make a big difference in how well these fragrant flowers grow.

Best Locations

Sweet peas love sunny spots. Pick a place that gets at least 6 hours of direct sunlight daily. They do best in areas with good airflow, which helps prevent diseases.

A sturdy support structure is a must. Trellises and fences work great. Make sure it’s in place before planting to avoid disturbing roots later.

Planting Times

Timing is crucial for sweet peas. In mild climates, plant in the fall for spring blooms. For colder areas, start seeds indoors 4-6 weeks before the last frost date.

Spring planting works too. Sow seeds directly in the garden as soon as the soil can be worked. This is usually when temperatures consistently stay above 40°F (4°C).

For summer-long blooms, plant in batches every 2-3 weeks. This way, you’ll have fresh flowers throughout the season.

How to Plant

Before planting, soak seeds overnight in warm water. This softens the seed coat and speeds up germination.

Dig a trench about 4 inches deep. Space seeds 3-4 inches apart. Cover with 1 inch of soil.

As seedlings grow, gradually fill in the trench. This encourages deep root growth, making plants more drought-resistant.

For indoor starts, use biodegradable pots. This allows for easy transplanting without root disturbance.

Water well after planting, but avoid overwatering. Sweet peas don’t like wet feet. Keep soil moist but not soggy.

Sweet Pea Flower Care

Sweet peas love cool weather, rich soil, and lots of water. With the right care, these flowers will fill your garden with beautiful blooms and sweet scents.

Soil

Sweet peas grow best in rich, well-draining soil. Mix in plenty of compost or aged manure before planting. The soil pH should be between 7.0 and 7.5. If your soil is too acidic, add some lime to raise the pH.

Prepare the soil by digging it at least 12 inches deep. This helps the roots grow strong. Add a layer of mulch around the plants to keep the soil moist and cool.

Sweet peas are heavy feeders. They like lots of nutrients. Work in a slow-release fertilizer when you plant them.

Sunlight

Sweet peas love the sun but not too much heat. Give them full sun in cool climates. In warmer areas, they do better with some afternoon shade.

Plant them where they’ll get at least 6 hours of sun each day. The morning sun is best if you have an available spot. This will help to dry the dew on the leaves, which can prevent diseases.

If you live somewhere hot, try planting sweet peas near taller plants. These can provide some natural shade in the afternoon.

Temperature Tolerances

Sweet peas are cool-season flowers. They grow best when temperatures are between 55°F and 65°F. They can handle a light frost but will stop blooming when it gets too hot.

In warm climates, plant sweet peas in fall for winter and spring blooms. In cooler areas, plant them in early spring as soon as the soil can be worked.

Some varieties can tolerate temperatures up to 90°F. But long stretches of hot weather will make them stop flowering.

Watering

Sweet peas need consistent moisture. Water them deeply once or twice a week. The soil should be moist but not waterlogged.

During dry spells, water more often. Check the soil with your finger. If it’s dry an inch below the surface, it’s time to water.

Use a soaker hose or drip irrigation if possible. This keeps the leaves dry and helps prevent fungal diseases.

Fertilizing

I feed sweet peas every 2-3 weeks with a balanced, water-soluble fertilizer. Look for one with equal parts nitrogen, phosphorus, and potassium.

Start fertilizing when the plants are about 6 inches tall. Stop when they start flowering. Too much nitrogen can lead to lots of leaves but few flowers.

A tomato fertilizer works well for sweet peas. It has the right balance of nutrients to encourage blooms.

Pruning

Pinch off the growing tips when plants are 4-6 inches tall. This encourages bushier growth and more flowers.

Remove faded flowers regularly. This process, called deadheading, keeps the plant blooming longer.

If you’re growing climbing varieties, guide them onto their support as they grow. Tie them gently with soft twine or plant ties.

Pest Control

Sweet peas can attract aphids, thrips, and slugs. It’s prudent to check your plants frequently for signs of pests.

For aphids and thrips, I typically spray the plants with a strong jet of water. This knocks off the pests. You can also use insecticidal soap.

Place beer traps or copper tape around plants to deter slugs. Hand-pick any you see in the evening when they’re most active.

End of Season

As the season ends, I always let some flowers go to seed. Collect the dry seed pods for next year’s planting.

Cut back the vines once they’ve finished blooming. Add them to your compost pile if they’re disease-free.

Clean up any fallen leaves or debris. This helps prevent diseases from overwintering in your garden.

Overwinter Care

In mild climates, sweet peas might survive winter. Cut them back to about 6 inches tall and mulch heavily.

In colder areas, sweet peas are usually grown as annuals. Plant them fresh each spring or fall, depending on your climate.

If you want to try overwintering, choose a sheltered spot. Plant against a south-facing wall for extra warmth.

Recommended Types

Sweet peas come in many beautiful varieties. Here are some of my top picks:

• ‘Albutt Blue’ is a popular choice with pretty white and blue flowers. It smells amazing and climbs well.
• ‘Royal Family Mix’ gives you a rainbow of colors. You’ll get pink, purple, white, and red blooms all season long.
• For pure white flowers, try ‘White Supreme’. Its crisp petals look lovely in bouquets.
• If you love pink, plant ‘Mammoth Deep Rose’. The big, ruffly flowers are a showstopper.
• ‘Cupani’ is an old variety with deep purple and maroon blooms. It’s great for gardeners who like vintage charm.
• Don’t forget about dwarf types! ‘Knee-Hi Mix’ grows only 3 feet tall, perfect for containers or small spaces.

Propagating

Sweet peas don’t transplant well once established. It’s best to sow them from seed where you want them to grow.

To save seeds for next year, let some flowers go to seed. Collect the dried pods when they turn brown and split open. Store seeds in a cool, dry place until planting time.

Remember, sweet peas are annuals. They complete their life cycle in one growing season. For continuous blooms, plant new seeds every few weeks throughout spring.

Best Companion Plants

Sweet peas get along well with lots of other plants.

Climbing plants are perfect partners. Jasmine, clematis, and climbing roses all grow nicely with sweet peas. These vines will grow together beautifully on a trellis or fence.

Flowers that attract helpful insects are good choices too. Try planting:

• Marigolds
• Pansies
• Sweet alyssum

These pretty blooms bring in bees and butterflies to pollinate your sweet peas.

Veggie lovers, don’t feel left out! Sweet peas can hang with edible plants too. Green beans and cucumbers are great options. They’ll climb right alongside your sweet peas.

Low-growing plants work well at the base of sweet peas. Think lettuce or spinach. They’ll create a lovely ground cover without competing for sunlight.

Remember, sweet peas like cool weather. Pick companions that enjoy similar conditions for the best results.

Garden Design Tips

Sweet peas need support to grow, so your garden design plans will need to accommodate areas with fencing or trellis.

For a charming look, mix sweet peas with other climbing plants. Clematis or morning glories work well. The different colors and shapes create a lovely display.

Don’t forget about containers! Sweet peas grow nicely in large pots or window boxes. Just be sure to provide support for them to climb and cascade.

Consider color when planning your sweet pea garden. These flowers come in many shades. You can create a rainbow effect or stick to a specific color scheme.

Here are some fun color combination ideas:

• Pastel mix: Light pink, lavender, and cream
• Bold contrast: Deep purple and bright white
• Sunset inspired: Orange, red, and yellow

Sweet peas make great cut flowers too. Plant extra so you can enjoy bouquets indoors.

Lastly, think about scent. Some varieties are more fragrant than others. Plant sweet peas near seating areas or windows to enjoy their sweet smell.

Common Problems and How to Deal with Them

Sweet peas can face a few common challenges as they grow.

Pests can be a pain for sweet peas. Aphids love to munch on these flowers. To get rid of them, spray the plants with a mix of water and dish soap. For bigger bugs like slugs, try putting coffee grounds around your plants.

Yellow leaves might mean your sweet peas are thirsty. Sweet peas need deep, well-draining soil. If the soil feels dry, give them a good drink. But be careful not to overdo it!

Sometimes sweet peas refuse to bloom. This could be because of too much nitrogen in the soil. Use a fertilizer with less nitrogen and more phosphorus to encourage flowers.

Powdery mildew can make your plants look dusty. To prevent this, make sure your sweet peas have good airflow. If you see mildew, remove the affected leaves and spray the plant with a mix of milk and water.

Root rot can occur if the soil is too wet. To avoid this, plant sweet peas in well-draining soil. If you spot yellowing leaves, check the roots. If they’re mushy, it might be time to start over.

Further Reading and Recommended Resources

Want to learn more about growing sweet peas? Here are a few of my favorite books and online resources:

Books

• “The Sweet Pea Book” by Graham Rice – A must-read for sweet pea fans.
• “The Fragrant Path” by Louise Beebe Wilder – Lovely info on scented plants.
• “The Flower Gardener’s Bible“ by Lewis and Nancy Hill: A staple for any gardener’s library, offering comprehensive advice on a wide range of flowers, including sweet peas.
• “Annuals for Every Purpose” by Larry Hodgson: This book provides detailed advice on growing annual flowers, including sweet peas, and offers practical tips for every type of garden.
• “Taylor’s Guide to Annuals” by Barbara W. Ellis: A guide to a variety of annuals, including sweet pea flowers, featuring care tips, planting strategies, and design ideas.
• “The Encyclopedia of Annuals and Perennials” by Colston Burrell: A resourceful book for gardeners covering a wide range of annuals and perennials, including sweet peas.

Online Resources:

• National Gardening Association (NGA) – Cosmos Growing Tips: The NGA offers practical advice for growing and caring for cosmos flowers, with tips for planting and maintenance.

Forums and Communities

Getting advice from fellow gardeners can be incredibly useful. Websites like GardenWeb and The National Gardening Association have forums where people share their experiences and tips for growing cosmos flowers.

YouTube Channels

For visual learners, channels such as Garden Illustrated offer practical video tutorials. Georgie, the host, covers everything from planting techniques to seasonal care tips.

Wrapping Up

Sweet peas are a joy to grow. Their fragrant blooms and climbing vines add charm to any garden. With the right care, these flowers will thrive and bloom for months.

Remember to plant sweet peas in rich, well-draining soil. Give them plenty of sun and water. A sturdy support structure is key for their climbing habit.

Regular deadheading keeps the blooms coming. Pinch off spent flowers to encourage new growth. This simple task can make a big difference in how long your sweet peas flower.

Don’t forget to enjoy the fruits of your labor! Cut some stems for indoor bouquets. The sweet scent will fill your home with a lovely fragrance.

Further reading: Best Types of Annuals for Full Sun Gardens.