How to Grow Everlasting Sweet Peas?

As the name suggests everlasting sweet peas are perennials that grow back every year from rhizomes.

Unlike annual sweet peas, perennial sweet pea flowers don’t have fragrance. But, they will beautify your gardening fence.

This drought resistant flowering plant bloom in summer and it needs cool soil with good air circulation.

Even if you’re just starting your gardening experience, you can grow everlasting sweet peas with little care.

As these plants are climbers they need to be supported with wooden or metal trellis.

Colorful blossoms of everlasting sweet peas will add aesthetic appeal to your garden fence.

Growing Everlasting Sweet Peas from Seeds

growing sweet peas in hanging baskets

Soil: Well drained fertile soil (Acidic or alkaline or neutral)

Sunlight: Full sun or partial shade

Water: Water when the top 1 inch of the growing medium is dry

Drought resistant

Blooms in summer

This is deciduous plant, so you must cut down everlasting sweet pea to ground level in fall. It grows back from rhizomes in growing season.

Fortunately, Lathyrus latifolius has no serious pest problem.

Lathyrus latifolius or perennial sweet pea plant grows in full or partial sun. It needs well-drained moist soil that can retain moisture and supply required nutrients.

You can either grow them on slopes or allow them to climb along the wall side borders.

Its bright flowers attract brimstone butterflies and other pollinators to your garden.

Though there are different types of Lathyrus, everlasting sweet pea needs to be supported with canes, trellis or netting.

This plant bloom in summer and come backs every year. But, unlike Lathyrus odoratus, flowers of this sweet pea plant don’t have fragrance.

If you’re looking for colorful blossoms without scent, then you’ll love to grow everlasting sweet peas.

While growing you must ensure the plant is healthy and avoid pests.

Fortunately, Lathyrus latifolius has no serious pest problem.

How to Plant and Grow Perennial Sweet Peas from Seeds?

Seeds need to be soaked for 24 hours before sowing them in seedling tray. You must maintain ideal temperature of about 65F to germinate seeds.

Once seedlings reach certain height harden off gradually and shift them to garden soil or container. You can also grow bushy sweet peas in hanging baskets.

Particularly, everlasting sweet pea is drought tolerant and can also survive cold weathers.

It gets its ornamental appeal with its leafy wings on the stem.

Below mentioned are few essentials, if provided can make this flowering plant healthy.


Every plant including sweet pea needs sun exposure to make its food.

Without enough sunlight, sweet pea plant leaves turn yellow and starts to droop.

Like annual sweet pea, perennial sweet pea plant needs full sun and can grow even in partial shade with 3-6 hours of sun exposure.

In some regions, where especially in the South US, gardeners must save this flowering plant from afternoon sun.

Like its counterpart, everlasting sweet pea prefers cool soil temperature ranging between 55F to 65F.


Choose well-drained growing medium that is rich in nutrients. You can add old fully rotten compost to the planting hole.

Soil that fail to drain excess water can result in overwatering and root rot.


Watering frequency is one of the main aspects of growing sweet peas. Like most houseplants, this flowering plant is prone to overwatering.

While watering your sweet peas, you should check the growing soil for moist. Insert your index finger in the soil to inspect the moist level.

If top 1 inch of the soil is dry, water your plant. Else, wait for the soil to dry.


Apart from adding old compost while planting, you must add fertilizers that are rich in potash to enrich sweet pea plants in growing season.

Worm castings include high levels of nutrients that provide essential nutrients for plant growth and flowering.

Fertilize your everlasting sweet peas twice during growing season.

To increase blooming, you must add phosphorus rich fertilizers.

Avoid using nitrogen rich fertilizers, as it will encourage plants to grow big leaves with less flowering.

Also Read: Should I Water After Applying Fertilizer?

Pests and Diseases

According to North Carolina University, there are no serious pest problems for this ornamental plant.

However, you must inspect plant regularly for pests like aphids, slugs and snails.

When to plant everlasting sweet pea plants?

Cooler climate: Plant in early spring.

Warmer climate: Plant in fall.

How to propagate everlasting sweet peas?

Similar to annual sweet peas, you can grow perennials from cuttings.

  • Choose seedling that is 2 months old and cut the stem to propagate.
  • Place the cutting in a jar filled with water.
  • Keep the pot or jar near windowsill so that it gets enough sunlight to grow.
  • In 2-3 weeks you’ll notice roots popping out of the stem.
  • Plant this sweet pea cutting to potting soil mix.
  • After 6 weeks you’ll have a young sweet pea plant in your pot. (Source)

Do you cut back everlasting sweet peas?


This plant is deciduous, which means it drops all its leaves after growing season and goes dormant until it starts to grow again.

After growing season or in fall you should cut back perennial sweet peas to ground level.

Why are my everlasting sweet peas not flowering?

In sufficient sunlight, dead heading flowers or low nutrients in the soil can be reason why your everlasting sweet pea plant is not blooming.

  • Ensure to expose your plant to full sun or 6 hours.
  •  Add phosphorus rich fertilizer to encourage blooming.
  • Snip dead flowers, this will stimulate the plant to bloom.

How to support everlasting sweet pea?

Except busy variety most sweet pea plant are climbers and need to support.

You can use any structure to allow these vines to grow.

Wooden fence, trellis, fences or support mesh can be used to support this sweet pea plants.

Important Tips to Grow Everlasting Sweet Peas in Container

  • Water and sunlight are essential things to grow healthy sweet pea plants.
  • In dry weather, check the soil moisture regularly and water generously so that the water easily reaches deep roots of the plant.
  • But, make sure you don’t overwater the plant. Excess water accumulated under the soil can rot your plant roots and result in discoloured leaves.
  • As mentioned many time in this article, this plant need full sun to thrive.
  • New shoots coming up must be tied to canes or trellis. Else, the plant tendrils can spread to neighbouring plants.
  • Pruning is one of the major tasks to encourage blossoms and growth of flowering plant.
  • Pinch off shoot tips of young sweet pea plant to encourage strong branches.
  • It will also improve flowering of your plant.
  • If you’re planning to grow everlasting sweet peas in container, then choose potting soil mix that includes garden soil, vermicomposting, perlite and sand.

Final Words

Growing everlasting or perennial sweet peas is easy. All you’ve to do is to choose best seeds, soak them overnight and sow them in early spring in a tray.

Maintain temperature 65F for germination and shift the seedlings to garden after couple of weeks.

Choose a location that gets full sun and support growing sweet pea plant with trellis.

To increase flowering of everlasting sweet peas, use fertilizer rich in phosphorus and potassium.

After growing season, you should stop watering and cut down the perennial sweet pea plant to ground level.