How To Grow Sweet Peas

Sweet peas have been a favorite among home gardeners and florist traders for centuries. It’s an annual flowering plant with soft, ruffled petals that resemble a butterfly’s wings. Its colorful and fragrant flowers, and long, straight stems make this plant desirable for flower bouquets, home décor, and adding color to your garden.

If you’re looking for a flowering plant that is easy to sow, grow, and maintain, why not try growing sweet peas? Here’s what you need to know about growing sweet peas in your garden. 

About Sweet Peas

sweet peas

Sweet peas (Lathyrus odoratus) are an excellent cut of flowers that make wonderful bouquets. Although they only have 4 to 5 days of vase life, their slender stems and fragrant blossoms are a delight to most gardeners. As the sweet pea flowers have a dainty floral scent, the buds and petals make an essential oil that is used in aromatherapy, cosmetics, and perfume blends. Sweet peas are also great when it comes to attracting pollinators to your garden.

Sweet peas, being an annual plant, lives for a year and dies after setting seed. They can be grown as climbing vines or tall bushes. Apart from the bush pea growing up to 2 to 3 feet, they can grow up to 9 or 10 feet with support. 

Sweet peas are a vine with tendrils that make them good climbers. They can easily be trained with the cordon method, to grow up and thrive. Sweet peas belong to the sweet pea family and can be eaten but they’re not edible. Eating sweet peas can cause discomfort and pain.

Sweet peas are native to the Mediterranean region. They symbolize blissful pleasure, and the upright clumping flower bunches also signify good wishes, gratitude, friendship, and goodbyes.

Types of Sweet Peas

sweet peas backyards

There are almost 110 varieties of sweet peas that belong to the Fabaceae family, but let’s look at some of the most popular types commonly grown in gardens.

  • Albutt Blue: Albutt blue sweet peas are white with the edges lightly touched with lavender. The flowers are not that big, but they are a must-grow for their scent alone. Grows to a height of 1.8 m and spreads to 0.5 m.
  • Almost Black: Almost Black sweet peas fall under the Grandiflora variety series holding clumps of highly perfumed dark maroon flowers which are almost black. Used mainly in floral arrangements and gardens. This plant grows to a height of 2m and spreads up to 30 cm.
  • America: America sweet peas are also known as America, an award-winning cultivar that grows to a height of 6 feet. It is a climbing plant that grows very fast with attractive large flowers.
  • St George: St George sweet peas have mixed colors of red and white just like the colors seen on the St George flag. These make excellent for cutting as the blooms last well in water.
  • Promiscuity: Promiscuity sweet peas are also known as Promiscuity which produces stunning, strongly fragrant flowers which are bicolored in pink, purple, and white. The blooms last well in water.
  • Lathyrus vernus: Lathyrus vernus, also known as Alboroseus  is a hardy and bush-forming type of sweet pea. They’ve tiny pink flowers in April and grow up to around 35 cm in height.
  • Lathyrus latifolius: Lathyrus latifolius, also known as White Pearl, flowers best from June to late August. They’re perennial climbers.
  • Matucana: These are known as the old-fashioned sweet pea that has scented two-tone purple flowers. They bloom in summer and are great for picking. These are very hardy type of sweet pea that is annual.
  • Lipstick: This is a free flowering tough type of sweet pea that grows vigorously reaching up to about 2.2 metres in height and requires support. The blossoms are large and frilly with a wavy-edged look. They’re a strong performer when it comes to fragrance.
  • Lord Nelson: Lord Nelson is a hardy type of sweet pea that is grown annually for picking. The flowers are blue and very fragrant in summer. These grow up to 2 meters in height and require support.
  • Painted Lady: Painted Lady is a hardy type of sweet pea grown annually. They’re an old-fashioned type that has bi-colored blossoms of pale and dark pink which are scented and make great early flowers.

Planting, Maintaining and Caring for Sweet Peas

planting sweet peas

When growing sweet peas, there are some important factors to consider. Let’s take a look.

Temperature and Climate

Sweet peas prefer cooler conditions. The suitable temperature needed for germination is 40 t0 50 degrees Fahrenheit. The appropriate USDA planting zones are 7 to 9. It’s best to start planting sweet peas from late October to mid-November. Planting can be done into December if the areas are not extremely cold. Planting in late fall helps the seed to germinate and send most of the energy for root development.

During the cold climate, the shoot does not start growing; they make arrangements for the plant to grow when the warm season slowly starts. As soon as the weather starts to warm again the shoot starts its growth and this is when the plants become visible. Then they grow rapidly to produce flowers in early summer.

As the temperature increases the growth of the sweet pea decreases as they cannot tolerate heat greater than 80 degrees Fahrenheit. To avoid this, it is important to provide shade for better results.


soil for plants

Sweet peas thrive in well-drained soil that retains moisture. Overly wet soil can cause the seeds to rot. When watering your sweet peas, remember to be careful that the water does not puddle up causing harm to the plants. When sowing the seeds should at least be 1 inch deep and 3 inches away from each other. Sweet peas can also be grown in pots or containers. Usually, sweet peas that are soil grown to tend to be taller than potted plants.


Sweet peas like cool roots and are not that friendly to sunny conditions when the temperature of the soil is high therefore would prefer shaded areas. If the soil temperature is low, it can survive in sunny conditions.


watering can

Sweet peas do not need much water so watering them once a week would keep the soil moist enough for the plants to grow. During the growing phase, the soil should maintain even moisture.

Water them regularly during warmer temperatures. Watering the plant early in the day is more advisable to prevent buds from falling off, stop yielding, and avoid plants from getting roasted.


Using a mixture of OCP eco-seaweed and OCP eco-amino gro every 2-3 weeks will help your sweet peas grow and blossom. You could also use fertilizers high in potassium like tomato fertilizer. Pinching out tips of early growth on small plants will allow sweet peas to become denser and have more flowers.

When they start to flower, try a second application of dolomite or lime to the soil. This will raise the alkalinity of the soil which your sweet peas will love.

As your sweet peas fade out of bloom, deadhead the flowers by pinching or cutting off the flower stems just below the spent flower. This will allow for more flowering next round.

Adding a little bit of blood meal to the soil will help the stems grow longer and be sustainable enough for cuttings.


Sweet peas are grown from seeds and can be directly sown into the soil. Soaking the seeds in a bowl of warm water overnight will allow the seeds to absorb a little moisture before sowing them into the soil. This will speed up the germination process. Another way to activate germination is to nick the seed coat with a knife but avoid damaging the ‘eye’ area of the seed.

When sweet peas are done with flowering, seed pods will develop. Let the seed pods dry in a paper bag brown color. As the seed pods dry, they will naturally open to drop the seeds to the ground where new sweet peas would grow. Remember to collect some fully dried seed pods and store them in a warm dark place for the next season.

Sweet peas can also be grown via cuttings. You could cut a 5-inch piece of the stem just above a leaf pair and place the cutting in a rooting hormone solution for a few seconds and then place it in water. When you see the roots appearing you can plant the new sweet pea plant in the ground.

Pests and Diseases

aphids on plants

Here’s a quick look at some of the most common pests and diseases that can threaten your sweet pea plants.

Snails and slugs: Snails and slugs like to feed on the soft leaves of the seedlings. To avoid this, use OCP eco-shield pellets on the seedlings to keep them safe from these munching enemies. Another way to deter such pests away is to use beer traps or copper bands.

Powdery mildew: Powdery mildew is very common and occurs when the temperatures start to increase. To get rid of these it is better to use an organic fungicide spray as soon as you see the white powdery spots which are visible on the top and bottom of the leaf surfaces. This can replicate rapidly in warm and dry conditions producing new spores to spread the disease easily. This disease can cause the plants to die quickly so spraying the organic fungicide will help you to enjoy more flowers. 

Aphids and mites: Aphids and mites are sap-sucking pests that suck the sap of these plants and destroy them. For easy control from these, you can spray OCP eco-oil or OCP eco-neem.

The Take – Away

Sweet pea flowers are a great choice of plants to have indoors and in gardens. These flowers give the environment a warm fragrance and light up the surroundings with stunning colors. Sweet peas benefit the garden as a very good garden pollinator makes them highly desirable. Above everything, they are very easy to grow.