One of the simplest flowering annuals to grow from seed is the sweet pea. In the garden, sweet peas are frequently direct-seeded. Give them a location with full to partial sun and rich, loamy soil that is deep, wet, and well-drained. To improve the soil and make it more friable, add lots of organic matter (compost, well-rotted manure, leaf mold, or humus).
When they are planted at times with colder temperatures, sweet peas thrive. The “season” for cultivating sweet peas is different depending on the location. To enhance winter and spring blossoming in western North America, sweet pea seeds should be sown from August forward. Although harsh freezes can cause sweet peas to die back, the plants can withstand frost without suffering too much damage. In the west, sweet pea blooms can be enjoyed well into the summer because of cooler nighttime temperatures.
Sweet peas can be started inside early for transplanting or planted right away once the worst of the weather has passed in the drier plains regions. Sweet peas have been successfully cultivated in Colorado’s hot summers by cut flower producers who mulch thickly as the plants mature and the temperature rises.
In the south, plant seeds in November or December for fresh cut flowers in early spring. In the non-coastal mid-west and northeast, start seeds indoors in February and transplant them outside after the ground thaws. In April, seeds can also be planted directly into prepared garden soil. The northeast’s coastline regions are also great places to raise sweet peas for the spring.
For sweet peas to bloom magnificently in your yard, you will need about 50 days of chilly temperatures (below 60 F). The seed coat of the sweet pea is tough and insoluble in water. There is no proof that sweet pea soaking will promote germination. A sweet pea seed’s outer layer can be punctured to allow for quick hydration, which speeds up and increases germination. The sweet pea seed coat can be easily nicked by scoring it with a nail cutter. When the soil is between 13 and 18 C or 55 to 65 F, sweet pea seeds will begin to sprout.
In holes that are about two inches (two knuckles) deep, plant seeds. Fill each hole with two to four seeds, and spacing them four to six inches apart. Till seeds have sprouted, thoroughly water and maintain soil moisture. Germination should occur within 10 to 21 days. Water the seedlings frequently once they start to grow to encourage robust, wholesome growth. Thin out the seedlings when they are three to four inches tall, spacing the strongest-looking plants four to six inches apart. You can enjoy your sweet peas for a longer period of time by sowing seeds once a week throughout a number of weeks.
Grow them in four-inch plastic or peat pots filled with a seed-starting mixture devoid of soil. Put two or three seeds into each container, each one being pushed an inch into the potting soil. Put the pots in a cool, dark location after covering with mix and water. Watch for new shoots to appear above the earth after about 10 days. Bring the plants outside into the sunlight at that stage. Keep them cool (below 55°F); if you keep them in a heated room, they won’t be hardy enough to move outside without a lot of time to harden off. Reduce the seedlings to one plant per pot until they have two sets of true leaves. As soon as the soil is workable, transplant into the garden about a month before the last date of frost because the shoots are hardy and won’t be affected by light frost. 12 inches should separate dwarf bushy forms, and 6 inches should separate climbing variety.
To avoid harming the roots, it is advisable to plant the stake or support with the seed or transplants when planting tall, long vine sweet peas. Although trellises are the most typical supports, there are various ways to climb. Sweet peas may climb on bird netting strung between two stakes, twine, string, or fishing line hung from the top of a split rail fence, a bamboo teepee, and brush stakes. If the support isn’t up against a wall, scatter seeds all around it to create a stunning display of blossoms that are visible from all angles. A four to six-inch layer of organic mulch will keep the roots cool and lengthen the growing season once the plants have been thinned out.
Avoid overfertilizing to avoid producing lots of very deep green foliage but few blooms. For the initial plant development, a 20-20-20 slow release fertilizer combination that is balanced works well. As an alternative, sweet peas benefit greatly from organic fertilizers. Composted manure mulching will help keep the soil moist and supply nutrients for healthy plant growth and blossoming.
When flowers start to fade, deadhead the plant if blooms are not frequently pruned. The plant will produce fewer flowers overall if seedpods are allowed to develop. More flowers will result from removing spent blooms.
Similar to other direct-sown seeds, the first difficulty for sweet peas is avoiding being devoured by rapacious birds, mice, squirrels, and other animals. Sweet pea seedlings are particularly susceptible to bird, slug, and snail damage if planted in the fall in a warm area.
Preventative actions frequently stop a problem in its tracks before it really has a chance to begin. For healthier plants, abide by these recommendations. Sweet peas should be planted in a region with sufficient airflow. Wet leaves are a magnet for fungus, so water early in the day so they are dry by dusk. Consider sweet peas as a type of food crop. Planting locations should be rotated so that sweet peas are only cultivated in one location every four years. Do not plant sweet peas where other legumes are flourishing or were previously planted. Garden peas, all varieties of beans, peanuts, and clover are examples of legumes.
In particular, certain specialized nurseries or garden centers may sell sweet pea plants. There might be sweet pea plantings in ready-made containers, creating an instant garden. When buying sweet peas, search for plants in individual peat or earth-friendly pots as they require special care when transferred. The better, the bigger the pot. Snip off any blooms or flower buds just before planting. Now is the moment to establish the roots thoroughly so they can support the needs of the developing plant. You will gain larger plants with a profusion of bigger flowers even though you give up early blossoms.
Plant in a pot or in garden soil that has been prepared. To protect the priceless roots from damage when transplanting, it is even more crucial to place the support first. Attempt to maintain the root ball’s unity. It should be planted at the same depth as when it was first emerging. Water it after gently firming the dirt around it. A week to 10 days should pass before mulching. Till the plants are well-established, make sure to maintain the mulch at least an inch away from the stem of the plant. Otherwise, you run the risk of suffocating the stem or potentially fostering bugs, illnesses, and insects.
Sweet peas entered the world of containers when “Cupid,” the first dwarf sweet pea, was introduced at the turn of the 19th century. Their small size makes them ideal for use in pots, urns, hanging baskets, window boxes, and other types of containers. Numerous varieties of dwarf sweet peas are offered in store-bought seed packets or through mail-order catalogs.
Sweet peas that climb are excellent container plants as well. Instead of placing one or two seeds in the center of the pot, place a circle of seeds an inch inside the rim of the pot, spaced a few inches apart. It is simplest to plant the support first, then scatter the seeds around it, in the constrained space of a container. Tomato cages make excellent supports for larger containers; the legs can be pressed into the potting soil. You can put a container of sweet peas in the garden in the early spring because sweet pea shoots aren’t affected by frost (at the same time youd plant seeds outside.)
Start trimming flowering stems for indoor bouquets when the first blooms show. You’re encouraging the plant to produce more flowers in addition to enhancing the lovely scent in the home. Every other day, during the morning hours when they are freshest, trim the stems. For climbing kinds, trimming lateral shoots that emerge from the base of the leaves will slow vegetative development, boost flower production, and improve airflow around the plant.
When you first arrange the stems, they will appear full. As the early blooms fade, the remaining buds will open. Make sure to get rid of any leaves in the vase that are submerged in water. If the base of each stem is trimmed off by 1/4 to 1/2 inch, a bouquet of sweet peas will easily last a week indoors. The water should also be changed every day.
The National Garden Bureau provided permission for this information to be republished. The person who wrote this fact sheet is Cathy Wilkinson Barash. Renee’s Garden provided the sweet pea image “Pastel Sunset,” while Bodger Seeds Ltd. provided the sweet pea images “Ocean Foam” and “Streamers Mix.”
Sweet peas can they withstand a freeze?
As annual plants, sweet peas (Lathryus odoratus) complete their whole life cycle in a single growing season. This traditional flower germinates well in cool environments, but if the plants are not covered, frost and freezing temperatures can cause damage to sweet peas. Direct sow sweet peas outdoors in late fall in warmer areas to enhance winter and spring blooms. Young seedlings can survive cold snaps if they are shielded from abnormally low temperatures.
Tip
Sweet peas can withstand a slight frost, but immature seedlings can freeze in temperatures below 25 degrees Fahrenheit. To ensure your cutting garden flowers will endure chilly nights in the early spring, protect sweet peas when low temperatures are anticipated.
Should I cover the peas to prevent frost?
Peas can survive in temperatures as low as 28 degrees Fahrenheit (-2 C.) Peas and pea seedlings will be fine as long as temperatures don’t drop below this level.
Peas can withstand the cold in temperatures between 20 and 28 degrees F (-2 to -6 C), although they will experience some harm. (This is presuming that there is no insulating layer of snow when the cold strikes.)
The plants can survive temperatures as low as 10 degrees Fahrenheit (-15 degrees Celsius) or even 5 degrees Fahrenheit (-12 degrees Celsius) if snow has fallen and covered the peas.
The ideal temperature range for pea growth is between 50 and 70 degrees Fahrenheit (10 and 10 degrees Celsius) throughout the day and night, respectively. But even outside of these ranges, peas can still develop and bear fruit because these are the ideal conditions for their growth.
Folklore might suggest that you plant your peas by the middle of March, but it is always a good idea to consider your region’s climate and weather patterns before doing so.
What temperature causes sweet peas to die?
Pea plants generally prefer lower temperatures. According to Utah State University Extension, for pea plants to continue growing, soil and air temperatures must be below 80 degrees Fahrenheit. Pea plants may become stressed by heat and dryness and lose their blossoms, which reduces the amount of peas they produce. Light frosts, which are defined as air temperatures between 28 and 32 degrees Fahrenheit, can be tolerated by young pea plants. According to Cornell University, these light frosts encourage more rapid development and more pods in immature frost-hardy pea plants.
However, peas, like other cold-weather vegetables, can suffer from too low temperatures. Younger pea plants may be harmed by hard frosts, which occur when air temperatures fall below 28 degrees Fahrenheit, depending on their growing environment. Older plants are more vulnerable to the effects of cold weather and frequently die when the temperature falls below 32 degrees. In spring plantings, this issue is uncommon, but it occurs more frequently in the fall. Fall frosts nip the peas just as they’re about to mature.
Can sweet peas survive a little frost?
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.