How to Plant, Grow, and Care for ‘My Navy’ Sweet Peas

Sweet Peas enchant with bountiful cottage-style blooms and delicious fragrance. In this article, gardening expert Melissa Strauss shares all you need to grow deep violet 'My Navy' sweet peas!

Close-up of blooming "My Navy" sweet peas in a garden against a blurred green and yellow background. The My Navy sweet peas exhibit a captivating appearance with their deep, velvety navy blue petals, exuding a sense of richness and sophistication. The flowers are butterfly-shaped, with slightly corrugated petals.

Contents

Overview

Close-up of My Navy Sweetpeas flowering plants in the garden. The "My Navy" sweet peas showcase a captivating and deep navy-blue hue.The flowers feature delicate, ruffled petals that unfold in an elegant, spiral-like fashion, creating a visually appealing bloom. The slender stems of the plant support clusters of these enchanting navy blossoms, creating a striking contrast against the lush green foliage.
Plant Type Frost-tolerant annual
Family Fabaceae
Genus Lathyrus
Species Odoratus
Native Area Italy
Exposure Full sun to partial shade
Height 8’
Watering Requirements Moderate to high
Pests & Diseases Root rot, powdery mildew, slugs and snails, aphids, thrips, spider mites, botrytis
Maintenance Moderate
Soil Type Rich, loamy, moist, well-draining
Soil pH 7.0-7.5 alkaline

What are ‘My Navy’ Sweet Peas?

View of blooming plants against a light sky. The  plant is characterized by its slender vines adorned with lush, deep green foliage. The leaves are composed of multiple leaflets arranged in a pinnate or feather-like pattern along the stem, providing a verdant backdrop for the captivating display of delicate, navy-blue flowers. Each bloom features intricately ruffled petals.
The deep blue-violet flowers bloom heavily in spring.

‘My Navy’ is a stunning variety of vining sweet pea. Its deep blue-violet flowers are favored by pollinators, and their wonderful scent is a delight in the garden or cut flower arrangement. These non-edible members of the legume family are prized for their soft foliage and wonderful blooms. 

These cool-weather plants grow quickly and bloom heavily in the spring, then fade just as quickly in the heat of summer. The most distinct feature is the flower color. The richly pigmented shade of nearly navy looks amazing on its own or combined with another, lighter variety. 

History

Close-up of a blooming plant in a garden against a background of a blurred flower bed. The plant has graceful vines adorned with lush green, pinnate leaves. The foliage serves as a verdant backdrop to the captivating clusters of unique navy-blue flowers. Each blossom is characterized by delicate, ruffled petals that elegantly unfurl, forming spiral-like blooms.
This flowering vine was first cultivated in the 1690s by Francisco Cupani.

Sweet peas were first cultivated in the 1690s as garden plants by a Sicilian monk named Francisco Cupani, who shared his seeds with various plant enthusiasts across Europe.

Some of the most noteworthy contributions to the breeding of this flowering vine are attributed to a gardener named Silas Cole, who worked for the (Princess Diana) Spencer family. His accomplishments involved even larger and more bountiful blooms known for their flamboyant, ruffled petals

Native Area

Close-up of blooming multi-colored flowers in a sunny garden. The  plant is characterized by its graceful vines adorned with lush, deep green foliage, providing a verdant backdrop for the stunning display of flowers. The leaves are composed of multiple leaflets arranged in a pinnate or feather-like pattern along the stems, enhancing the plant's overall lushness. Clusters of enchanting navy-blue, pink and red flowers, featuring delicate and ruffled petals, adorn the slender stems.
Sweet peas are possibly native to China and Sri Lanka.

While there is some discussion that questions whether sweet peas may be native to areas of China and Sri Lanka, the first recorded plants were those belonging to Cupani.

The native range includes Sicily, where they were first cultivated as garden plants, as well as Southern Italy, the Aegean Islands, and Malta.

Characteristics

Close-up of bloomis under sunlight in a garden. The plant is characterized by its vigorous growth, featuring slender vines adorned with lush green foliage that serves as a backdrop for the striking navy-blue flowers. Clusters of the enchanting navy blossoms, each showcasing delicate and ruffled petals, elegantly adorn the plant's stems, creating a captivating display.
‘My Navy’ features long, strong stems with ruffled, fragrant violet flowers.

The ‘My Navy’ variety is most noteworthy for its flowers. Long, strong stems sport large flowers with ruffled petals in an incredibly rich shade of violet. The flowers bloom in groups of four or five per stem, and in addition to their striking appearance, they are highly fragrant as well. 

The central vines grow rather tall, at around eight feet long. They are climbers that cling to whatever their curling tendrils come into contact with. These are heavy bloomers, with many long stems growing from the central vines, blooming through the spring. 

Uses

Close-up of an attractive modern arrangement. The artichoke plant produces a striking flower bud that consists of tightly packed, overlapping bracts with a deep green hue. Giant alliums produce towering flower stalks crowned with oversized spherical blooms. Each bloom is composed of numerous small purple star-shaped flowers densely packed into a globe-like cluster. The "My Navy"  flowers are enchanting and captivating, featuring a rich, deep navy-blue hue.
These non-edible members of the legume family are grown for ornamental and floristry purposes.

Although they are members of the legume family, sweet peas are not edible like some of their close relatives. The seeds, in particular, are poisonous, so they should be planted away from the vegetable garden to avoid confusion. The seed pods do resemble other types of pea pods. 

They are most often grown for ornamental purposes, as well as for use in floristry. Their wonderful scent and rich symbolism make them popular for use in weddings. They can also be used as a cover crop, as they are nitrogen fixing, so they can enrich the soil for next season’s plants.

Where to buy

My Navy Sweet Pea Seeds

My Navy Sweet Pea Seeds
  • Spectacular Sea of Blossoms
  • Intense Violet-Blue Color
  • Large, Lightly Fragrant Blooms
  • Versatile Bouquet Component
  • Pollinator Attraction and Deer Resistance
View at Botanicalinterests.com

Planting

Close-up of female hands holding a small pot with a sweet peas seedling in a greenhouse above a table with many different potted seedlings. The woman is wearing a striped white and brown long sleeve. There are also terracotta pots with gardening tools on the table.
Direct sow in late fall for warmer climates or very early spring for cooler climates, spacing seeds six inches apart.

Sweet peas are cool-weather plants and are also somewhat frost tolerant, so the time of year to plant them varies by climate and region. In warmer climates, seeds can go into the ground in late fall. They will grow through the winter and begin blooming early in the spring for an extended blooming period. 

If you are planting in a cooler climate, wait until very early spring or late winter and plant your seeds as soon as the ground is workable. In climate zones north of Zone 7, they begin blooming later in the spring and continue into the early summer.

Direct sowing is the recommended method of planting sweet pea seeds. Sow your seeds in groups of three, with six inches between groups. Germination takes about 10-21 days under the right conditions. The ideal soil temperature for germination is 55°-65°F (13°-18°C). 

There is no evidence that these seeds benefit from soaking before planting. However, scoring your seeds lightly with a sharp blade may speed up and improve the rate of germination. Once your seedlings reach about three inches tall, thin them to one plant every six inches. 

How to Grow

The most important factor is planting at the proper time for your climate. Their cool weather habit and frost tolerance should be the main factors in terms of when to plant in your particular climate zone. 

Light

Close-up of blooming multi-colored flowers in a sunny garden. Among them there is the variety "My Navy" with charming navy-blue flowers. Each bloom showcases delicate, ruffled petals arranged in an elegant spiral, creating a visually stunning and intricate flower.
Sweet peas thrive in full sun, but in warmer climates, partial shade prevents dormancy.

In general, sweet peas need full sun to bloom their best. Six to eight hours of direct sun daily is a good number to shoot for, especially in cooler climates. Since summer heat is what causes them to go dormant in warmer climates, it is fine to plant your seeds in partial shade, with some protection from the hot afternoon sun. 

Giving the roots some shade in the afternoon will maintain a proper moisture level, which will keep your plants blooming and growing later into the year. The tops of the plants do need to get a significant amount of sunlight.

This combination can be achieved pretty simply by growing them on a trellis or other structure that creates shade near the ground but elevates the vines.

Water

Close up blue flower "My Navy" on a blurred green background. The petals have a navy-blue hue and are covered with drops of water.
Provide ample water but ensure well-drained soil to avoid waterlogged conditions.

These are moisture-loving plants. They need a fair amount of water to produce their sweet-smelling flowers and lush green foliage. That said, they do not like wet feet. However, that is controlled more by the soil composition than your watering habits. Water young plants every one to two days until they are established. 

Once your sweet peas are established, keep the soil moist but not soggy. How often you water will depend on your climate and the amount of rainfall.

Watering once or twice per week should be fine while temperatures are low, but as the heat begins to rise, you may need to water more frequently to extend the life of your plants.

Soil

Close-up of a sprout in rich, loose soil in the garden. The sprout emerges as a delicate and slender stem, showing vibrant green hues that signify new growth. Its stem is thin yet sturdy, supporting a pair of small, ovate leaves that unfold gracefully.
Ensure well-drained soil with added compost for moisture and fertility.

Provide soil with very good drainage. Because they like moisture around their roots, they can be susceptible to root rot. The composition of the soil is less important than the drainage, so in the case of clay-heavy soil that compacts easily, it’s a good idea to amend the soil with some well-rotted compost.

Another important element to consider is the fertility of the soil. They do like rich soil, so if you have poor soil, perhaps sandy or gravelly soil, you can increase the moisture retention and nutrient content of the soil by mixing in some compost or manure. A slightly alkaline or neutral pH is good for sweet pea soil. 

Temperature and Humidity

View of the field of "My Navy"  flowers. The "My Navy" plant is characterized by its vigorous vines, adorned with lance-shaped leaves in a rich green hue. Its flowers are the highlight, featuring deep, velvety navy-blue petals with a slightly ruffled texture.
Cool, humid climates with temperatures between 32°-60°F (0°-16°C) are ideal.

Because they are moisture-loving plants, it can be difficult to grow sweet peas in an arid climate. They prefer to have a humidity level at or above 50% for optimal health. In areas of high humidity, make sure to give your sweet pea vines proper air circulation, this will help to prevent fungal diseases.

They grow best in temperatures between 32°-60°F (0°-16°C). They are somewhat frost tolerant, which is how they can be planted in the fall in milder climates. Fall planting enables the plants to grow through the winter and begin blooming earlier in the spring. These plants thrive in cool weather and will enter dormancy when the weather gets hot in summertime. 

Fertilizing

Close-up of a gardener's hand holding granular fertilizer over the soil in a sunny garden. Fertilizers are scattered on the soil. These fertilizers are granular, round in shape, and grayish in color.
Mix organic or slow-release fertilizer into the soil before planting sweet pea seeds.

Before you plant your seeds, it’s a great idea to mix some organic fertilizer into the soil. These vines like a lot of nutrients, but if they are given too much nitrogen, the results will be a lot of green growth and significantly fewer flowers.

As your plant nears bloom time, feed it with a fertilizer that is higher in potassium for more blooms that are bigger and stronger. 

Maintenance

Close-up of a climbing pea vine wrapped around a bamboo pole against a blurred foliage background. The sweet pea leaves are lance-shaped and green in color, with a smooth texture and a slightly glossy surface.
Provide support for vining with options like trellises, tipis, or tomato cages.

Vining types, like ‘My Navy’, need to have some type of support on which to grow. A trellis or arbor can be wonderful but also more costly than simply offering them a spot by a fence or other existing structure. You can decide for yourself how cost-effective you want your structure to be versus how ornamental you prefer.

If you plant in the spring, pinching the stems will help to promote branching, leaving you with fuller plants that produce more flowers. When seedlings are about six inches tall, you can pinch or clip off the top of the stems just above a set of leaves. Two new stems will grow in its place. 

For fall plantings, pinching is typically not necessary. As long as your climate experiences some light frosts, the freezing and thawing will do the job of pinching off for you.

For sweet peas that continue to bloom for a long time, deadheading is vital. If flowers are left on the vine to go to seed, the plant will think that it is time to enter dormancy. Deadheading is a high-maintenance part of growing healthy flowers, but it also means that you will have a steady flower of cut flowers. 

Growing in Containers

Close-up of plant growing in a container in the garden. The plant features slender, twining stems that climb or trail, adorned with delicate, compound leaves composed of two leaflets. The leaves are bright green in color, oval-shaped, and smooth-textured.
Choose a spacious container with drainage, supporting structures, and ample root space.

Sweet peas grow quite well in containers, provided that the container has enough room for the roots to spread out. Once established, they do not like to have their roots disturbed. Choose a pot large enough that there will be no need to repot your plants. 

Select a container that is deep and wide enough to accommodate the root system of the plant, which has a relatively deep root system. Make sure the container has proper drainage holes, and include some type of support for your vines to climb on, such as a small trellis or tomato cage. 

Propagation

Close-up of a dry Sweet pea seed pod with several seeds inside on a beige surface. Next to the seed pod are Sweet pea seeds. Sweet pea seeds are small, round, and a deep shade of brown, with a smooth texture. The seed pod is elongated, slender and cylindrical in shape with a dry, papery texture.
Harvest the seeds as pods ripen, dry them, and store for planting later.

As annuals, ‘My Navy’ sweet peas are usually propagated by seed. At the end of the season, as your plant’s flower production slows down, leave a few flower stems intact to allow seed pods to form. 

If you intend to collect seeds for planting next year, you can allow your plants to go to seed at the end of the season when blooming slows down. Allow the seeds to ripen on the vine, and then harvest them, dry them, and store them in a cool, dry place until you’re ready to plant once again. 

Common Problems

These sweet-smelling flowers can fall victim to more than one type of garden pest. There are also a few diseases to watch out for when caring for these plants.

Pests

Close-up of a cobweb with tiny spider mites among the dry stems of a plant. Tetranychus urticae, commonly known as red spider mites, are tiny arachnids measuring less than 1 millimeter in size. They are reddish-brown to deep red in color, with two dark spots near the front of their bodies. These pests are characterized by their oval-shaped bodies and eight legs, which may appear to be covered in fine hairs.
Protect plants from harmful insects with care, ladybugs, or neem oil.

With their tender stems and foliage and sweet-smelling flowers, aphids, spider mites, and thrips are all fans of dining on these plants. They pierce the leaves and flowers with their mouthparts and suck out the sweet sap, depleting your plants of valuable nutrients.

Not only can this leave your plants without proper nutrients, but these insects also leave behind a sticky mess. Their excrement, called honeydew, remains on the plant, creating the perfect environment for black sooty mold to grow. This mold interferes with photosynthesis, which can leave your plants looking sad and unhealthy.

Keeping your plants healthy by caring for them and fertilizing them will help to protect them from insect damage. While you can help your plants withstand insect damage by keeping them healthy, it is important to control populations of harmful insects as well. For natural pest control, attract beneficial predator insects to the garden.

If you are looking for a more immediate method of insect control, neem oil is a safe alternative to other chemical pesticides. It can harm pollinators, so make sure to spray in the later afternoon, giving the neem oil time to dry before pollinators arrive in the morning. 

Diseases

Close-up of a leaf affected by powdery mildew against a blurred green background. A leaf affected by powdery mildew displays a powdery, white to grayish coating on its surface.
Proper drainage and air circulation prevent fungal and viral diseases.

Sweet peas love moisture, and sadly, so does fungus. Root and crown rot are common issues if they are not planted in properly draining soil. Another fungal issue that can affect these plants is powdery mildew, which can interfere with photosynthesis and look unsightly. Well-draining soil and proper air circulation are the best preventatives for fungal diseases. 

In addition to fungal disease, there are also a few viral diseases that can affect sweet pea plants. They don’t all kill the plant. Some just cause leaf discoloration, and some gardeners like that. However, some can kill the plant and stay in the soil to affect future plants. It is important to remove plants affected by these diseases and avoid planting other things in their place. 

When dealing with viral disease, make sure to dispose of infected plants away from other plants and deal with the larger issue, which is the virus remaining active in the soil. Most viral diseases can be eradicated by solarization, which involves harnessing the power of the sun to heat the soil to a high temperature, which kills the virus.

Frequently Asked Questions

Will Sweet Peas Bloom Again in the Fall?

Typically, they will not survive the heat of summer. However, in climates with mild summers, it can be possible to keep your plants alive. In this case, it is possible for them to bloom a second time when the temperature returns to the 60°F (16°C) range.

Are Sweet Pea Pods Toxic to Pets?

Yes, they are dangerous for both humans and pets when ingested. Keep these pods away from curious animals.

Do Sweet Peas Self-Seed?

Yes. They can self-seed in mild climate areas. Allow the seed pods to ripen on the vine. The pods will eventually burst, releasing the seeds, which can then germinate on their own.

Final Thoughts

With their sweet scent and gorgeous, richly colored blossoms, ‘My Navy’ makes a stunning and showy addition to the flower garden. Grow these pretty plants for cut flowers or simply to dress up a trellis, arbor, or other garden structure and bring a wide variety of pollinators to the garden.

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