When Sow Sweet Peas

Sweet peas are one of the few annual flowers with enduring appeal and rural charm. They appear to be the exact opposite of our hurried life as they twine languidly around a rustic trellis. Sweet peas are fantastic flowers for gardens and bouquets thanks to their alluring scent. For information on how to plant and care for sweet peas, read our Sweet Pea Growing Guide!

About Sweet Peas

The sour pea Lathyrus odoratus is an annual flower that looks great twining on a trellis or arch, growing in a cutting garden, border garden, or woods. Today, a wide variety of hues, from pearly white to ice cream pastels to ritzy magentas and inky purples, are available for the blooms.

Only their honey and orange blossom fragrance matches their delicate winged flowers. Their appeal has been ensured by the combination of their exquisite aroma and their capacity to generate a large number of flowers for the house over an extended time of cutting.

One of the keys to cultivating sweet peas is to sow them early. Sweet peas are incredibly tough, despite the way they appear fragile. Plant them in very late winter or early spring in USDA Hardiness Zone 7 or colder, as soon as the soil is dry enough to work with. (Don’t plant seeds after the last frost.

When Dr. Robert Uvedale, a teacher from Enfield, Middlesex, received seeds of this exceedingly fragrant annual in 1699 from a Sicilian monk named Francis Cupani, he brought the first sweet peas to Britain. In North America, they gained enormous popularity as garden plants and cut flowers. By the late 1800s, producers in California, especially W. Atlee Burpee, were exporting trainloads of sweet peas across the nation and creating numerous new varieties.

Some people liken the process of producing sweet peas to that of preparing pie dough. Some individuals are gifted, while others are not. This plant sprouts from large, manageable seeds that resemble peas. They are still rather challenging since they take a while to germinate. It’s worthwhile to experiment with various seeds every year.

When to Plant Sweet Peas

  • Sweet peas should be planted as soon as the soil is dry enough to work in very late winter or early spring in most places where frosts occur frequently (Zone 7 and colder). (Start sowing before the last frost! Most certainly, it will be too late.)
  • Plant sweet peas in the late fall (November) if you garden in a region with a mild winter climate (Zones 8, 9, or 10), so they can grow and blossom in the late winter and early spring. Six weeks before you plant the seeds, dig a trench and fill it with compost or well-rotted manure to obtain the greatest show. Sweet peas are gregarious plants that require a lot of nutrient-rich materials to flourish.

Sowing Sweet Peas Indoors

  • Start sweet peas inside in a seed tray to get a head start on the season in the coldest regions of the nation. Sweet peas can withstand light frosts, so plant out as soon as the soil can be worked in early spring, around 6 to 7 weeks before the last date for frost.
  • The seeds’ outer layer is softened and helped to germinate by soaking them overnight. Using a nail file to lightly score the outer shell can also be beneficial.
  • 2 seeds to a module is fine to sow the seeds, but keep in mind that their lengthy roots have a propensity to tangle and can make separation challenging. Sow the seeds around half an inch deep in each cell of a seed tray.
  • Scoop them out gently after they start to sprout their first pea-like leaves and place them in a larger container to harden off. One of the most reputable growers of sweet peas gave me the following piece of advice: “Treat the seedlings like I would treat my husband: put them in an unheated greenhouse, neglect them, and they will thrive.
  • Plant them outside as soon as the soil can be worked.

Sowing Seeds in the Ground

  • Sweet peas thrive when their roots are firmly planted in cold, wet soil and their heads are exposed to sunlight. Plant low-growing annuals in front of them if you can to provide shade for the roots.
  • Pick a spot that drains effectively. If your soil tends to be acidic, it is recommended to add some powdered lime to the surface.
  • Mix liberal amounts of compost or well-rotted manure into the ground to a depth of two feet to create a rich soil. (Learn more about adding amendments to the soil and getting it ready for planting.)
  • You should dig a beautiful, deep “compost trench” that is around 4 inches deep before planting.
  • After digging the trench, use a pencil to cut holes, place the seeds inside, and then press down on the earth to compact it and block out any light.
  • The seeds should be soaked in water for 24 hours prior to sowing. To hasten sprouting, nick the seeds with a nail file before planting. In a temperate climate, seeds don’t need to be soaked.

How to Grow Sweet Peas

  • Depending on the soil temperature, germination after planting can take anywhere from 7 to 15 days.
  • Fill in the trench gradually as the seedlings appear and develop. Hoe additional dirt toward them.
  • Keep the soil wet. Summer rains may be plentiful. Sweet peas can have bud drop; if you stick your finger into the soil bed to its first joint and the soil is dry, water them at the soil level and do so in the morning.
  • You won’t need to fertilize if you plant with a lot of compost and aged manure. Use high potash feeds if you do want to supplement the diet because nitrogen feeds promote excessive top development.
  • Mulch well once plants are planted to keep the soil cool and moist. Unless the soil becomes dry, you might not need to water your sweet peas if you mulch.
  • Pinch off the tops when plants are 6 inches tall, not sooner, as this will promote the production of side shoots too early.

Provide Supports

  • When temperatures rise above 65°F, sweet peas will begin to fade since they like chilly days and nights.
  • Sweet peas are true climbers, with the exception of the bush forms. Provide them with sufficient support for at least 6 feet. Some species can reach heights of nine or ten feet. A braided willow obelisk, bamboo poles in the tee-pee design, or a trellis are examples of other attractive supports. If you don’t have a fence or trellis, give them something to cling on, such chicken wire, bushy twigs, or brush.
  • Give the plants a good start by tying the first few stems to the support; the rest will follow. When they reach a height of 4 to 8 inches, use your thumb and forefinger to pinch out the middle growing point. Plants will grow stronger as a result.

Picking Flowers

  • Pick flowers frequently for bouquets so that the plant will focus its energy on producing additional blooms rather than seeds. Up until the first frosts, the more you pick, the more they produce.
  • Allow a couple of the final blossoms to mature into seedpods when the leaves begin to lose their color. On a windowsill, dry them, and then keep in an envelope in a dry location to sow the following year.

From miniature bedding kinds ideal for pots and borders without support to 8-foot-plus scramblers, there are sweet pea varieties for every setting.

These decorative peas are native to Sicily, where they have flimsy stems and a powerful orange-jasmine-honey aroma. Modern hybrids feature larger blooms and stronger stalks.

However, some of these contemporary kinds, despite having larger blossoms and more fashionable colors, lack the earlier sweet peas’ perfume. Sweet pea ‘Cupani’ is still rightfully well-liked and simple to grow. It has bi-colored flowers with maroon upper petals and violet “wings.”

The decadently fragrant “America” is an antique from 1896. When its petals open, beautiful red and white wavy stripes are revealed.

Look for antiques like the Sicilian “Old Spice” collection. Shades of white, cream, pink, lavender, and purple can be seen in this strain’s blossoms.

A new cultivar with enormous, creamy-yellow blooms with violet shading called “April in Paris” is aromatic.

Although the ordinary sweet pea is an annual, Lathyrus latiflolius, a perennial broad-leaved everlasting pea, is not fragrant. These clambering plants have a height of up to 6 or 7 feet, are hardy to zone 5, require little care, and bloom continuously from year to year.

  • An essential component of a late Victorian garden is the sweet pea. Because of their wide range of colors and aroma, Victorians adored sweet peas.
  • When the dew is still on the flowers in the morning, gather them. Their best aroma is at this time.

when to plant sweet peas

When between October and April, plant sweet pea seeds. Aim for late October or late November or late February or early March for the best outcomes because midwinter temperatures and light conditions aren’t the optimum. In April or May, sweet peas can also be planted directly into the ground. During a moderate period between March and May, sow your sweet pea seeds and plants.

What time of year do sweet peas grow?

The fragrant, sweet aroma that is released by the blossoms of annual sweet peas (Lathyrus odoratus) gives them their name. The fall, winter, and early spring garden seasons in warm, Mediterranean settings are perfect for this annual flowering vine because it prefers mild temperatures. In the spring and early summer, sweet peas grow best. Plant hardiness zones 4 through 7 of the United States Department of Agriculture are suitable for perennial sweet peas (Lathyrus latifolia). Depending on the cultivar, sweet pea blossoms come in a variety of hues, including white, purple, pink, red, orange, blue, and lavender.

Can sweet peas be seeded in the winter?

I adore annual sweet peas and believe that they are the most alluring and unforgettable garden flowers because of their beautiful scent, ruffled, winged blossoms, and treasure trove of radiant hues. These fluted beauties are excellent for cutting, and a tiny bouquet of them will fill a room with a mouthwatering aroma that makes me think of orange blossoms and honey. Sweet peas’ delicate, alluring scent is one of nature’s best-kept secrets; it has never been artificially imitated and is never overbearing or cloying.

There are now a large number of options available in a wide range of colors, from the most delicate sweet pastels to rich, vivid deep hues, including stripes and bicolors. You have a choice of classic, tall, quickly-growing vining sweet peas, non-climbing, dwarf kinds for beds and borders, and variants that cascade 8 to 10 inches in containers. All will beautify and fill the garden with a divine aroma in the spring and summer.

Sweet pea horticulture has a lengthy and fascinating history. On an island off the coast of Sicily in 1699, Father Cupani, a botanizing monk, was the first to gather sweet peas in the wild. Eckford, an Englishman, started hybridizing and selecting sweet peas in the 19th century, bringing in larger varieties in a wider spectrum of hues. These “grandifloras,” which are now referred to as “old-fashioned” or “heirloom,” were highly praised as cut flowers.

In this time, cultivars that were more suited to American garden conditions were created by American seed producers who were growing sweet pea seeds for export to the English market and for American seed catalogs. The coastal region near Lompoc, California, which is chilly, moderate, and windy, is perfect for growing sweet peas because the climate prevents the usual bee visitors from visiting the blooms, preventing cross-pollination and allowing for the preservation of exceptionally pure seed strains. Today, that region, together with England, New Zealand, and Tasmania, continue to supply a large portion of the world’s sweet pea seed.

You will find growing sweet peas to be quite gratifying if you follow the right guidelines and timing for planting. Sadly, sweet peas have a reputation for being challenging to produce, especially in the Midwest and Southeast. However, after speaking with successful sweet pea gardeners around the nation for many years, I am confident that sweet peas can thrive everywhere in the nation. Their beauty and smell are definitely worth the effort even in the rare places where they are more difficult to grow. Knowing when to plant the seeds and how to take care of sweet peas effectively are crucial.

When To Plant Sweet Pea Seeds

Sweet peas can be planted in the fall and again in the spring in regions with warm winters that experience prolonged rainy winters and cold summers, such as the Pacific Northwest. Sue, a gardener from Seattle and the creator of our website, plants seeds in April or May for “armfuls of blossoms” through September.

Plant seeds as soon as the ground is workable in rich, well-drained soil in locations with temperate winters, such as the mid-Atlantic states, which experience humid summers and early, unexpected summer heat. Don’t wait until you plant other annual flowers like sunflowers or cosmos or until the date of your last frost (sweet peas may withstand minor frosts). Your sweet peas won’t be developed enough to withstand the hot temperatures of early summer. If it doesn’t rain, make sure to water your sweet pea plants because they require constant moisture.

Nancy Hammer, a market gardener in Virginia, starts seeds indoors in jumbo packs or 4 inch pots in late March so that they can be planted outdoors as soon as they have two or three pairs of leaves. This allows her to get a head start on the season and prepare for the unpredictability of spring weather. In early to mid April, she also plants seeds straight in the ground. In this manner, she will be ready with healthy seedlings regardless of whether it is chilly and rainy well into spring or if sudden hot weather arrives.

Both Susan Keating in Maine and Jay Leshinsky in Vermont wait until the spring soil can be easily handled before planting, often in late April through mid May, in locations with extremely harsh winters like New England where the earth freezes hard and heaves. Additionally, they get a head start by starting seeds indoors a month to six weeks in advance and planting them outside as soon as the weather allows through May. In either case, keep in mind that sweet peas are unaffected by late, mild frosts. Sweet peas planted in the ground in northern regions in April and May will blossom fully in late summer and continue to do so virtually until the first frost. If the summers are particularly hot, choose a location where the vines will receive some afternoon shade and water if it doesn’t rain.