You’ve probably heard that you should soak your seeds if you’ve ever planted sweet pea seeds. Additionally, you’ve likely heard that you shouldn’t soak your seeds. Sweet pea seeds should become more pliable after soaking in order to facilitate easier germination. However, other authorities assert that soaking will lessen germination.
Each seed’s planting depth was meticulously measured using a pencil as a yardstick.
I have soaked sweet pea seeds, and they have grown, therefore the advise is confusing and contradictory. And they have grown since I sowed the seeds just as they are. If using fresh, high-quality seed, I find that sweet pea seeds typically germinate quite quickly, although I’ve never kept track of how many seeds have sprouted using soak or no soak techniques, and I never anticipated it to be 100% either way.
This fall, when I had a little more time, I decided to do a tiny experiment to compare the germination rates of soaked versus unsoaked seeds. It was only a test conducted in my boot room, so take from it what you will. I tried to set up this experiment as scientifically as possible (yeah, I remembered the days of science class papers consisted of “Aim,” “Method,” and “Conclusion” in high school).
I began with a small number of sweet pea seeds, all of the same kind and recently harvested this year. I separated the 100 uniformly shaped, sized, and colored seeds into two groups of 50 and put them in jam jars.
With moistened potting soil, I made two identical 50 cell seed trays in the meantime.
Planting Depth
In all the years I’ve grown sweet peas, I’ve always believed that the depth at which the seed is sown in the soil has a significant impact on how many young plants I get. A seed should generally be planted two or three times as deep as it is wide. However, I’ve discovered that planting sweet peas a bit shallower than that appears to work well for me; around a 1/4 inch seems to work nicely.
Because the rings on the end of a Ticonderoga pencil are nicely spaced at 1/4 inch (remove the eraser to make this work! ), I use it to create the holes for my sweet pea seeds. You can understand what I mean if you take a ruler and pencil.
For my “experiment,” I adhered to this rule and made sure that no more than 1/4 inch of potting soil covered each seed.
Temperature
Simply because that was the room’s natural temperature, the seeds were kept at a temperature of about 63F. Although sweet pea seeds can grow at lower temps, the one I had was this one.
Water
It is always amazing to see seedlings emerge, no matter how many times you see it! After I planted the seeds, I did not water them again until I saw germination take place, i.e., seedlings started to sprout.
Time
After 3 days, I saw the first symptoms of germination, but I didn’t count the seedlings in each group until 14 days had passed. On day 3, when I first noticed the babies emerging, I set the trays in full light.
Results
I appreciate you continuing to read, or did you quickly turn to the “results” section? In any case, I appreciate you reading my post. The fresh, high-quality, unsoaked seed prevailed! The unsoaked seeds germinated at a rate of 100%! As I indicated above, I don’t typically anticipate 100% germination rate from ANY seed I plant, so I was astonished by that.
The soaking seed also fared reasonably well. Only 3 seeds didn’t germinate, though. That indicates a 94 percent germination rate for the soaking seeds. Hey, that doesn’t seem too bad. And actually, a germination rate of 94% will be adequate for the majority of us. You probably won’t notice the sweet pea seed that doesn’t germinate if you soak 10 of them before planting them in your garden.
Notable: I only examined one variety of sweet pea. Each sweet pea cultivar will probably have a distinct rate of germination; however, the variety I tested had excellent germination rates whether I wet the seeds or not, and the seeds were also new and of high quality. On various sweet pea varieties, with older seeds, etc., you might observe varying results.
Before planting sweet peas, should I soak them?
To aid in seed germination, many individuals advise soaking seeds overnight before sowing. This is due to the hard outer shell of some types. Others, though, contend that soaking might make plants weaker.
However, you might try slightly shattering the seed’s outer shell right before sowing if you’ve previously had difficulties getting the seeds to germinate.
On the side opposite the seed’s black “eye” or scar, carefully nick the shell with a sharp knife or rub it with sandpaper.
When should peas be soaked before planting?
The majority of recommendations range from 4 hours to 48 hours. It’s fairly typical to soak overnight. To remove most wrinkles, soak for 24 hours. Seeds can be harmed by more than 48 hours.
What’s the key to successful sweet pea cultivation?
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 to, like 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.