- Why You Should Plant Sweet Peas in Your Garden This Year
- What Is Sweet Pea?
- When Do Sweet Peas Bloom?
- What Kinds of Sweet Peas Should I Plant?
- How Do I Grow Sweet Peas?
- Balsam (busy Lizzie)
- Having Fun with Impatiens Seed Pods
- There’s Just Something About Sweet Peas!
- How To Grow Sweet Peas
Why You Should Plant Sweet Peas in Your Garden This Year
Sweet peas are gorgeous additions to Southern gardens. They produce delicate, frilly, brightly colored blooms on tall, tangled stems, and they’re reminiscent of cottage gardens of the English countryside. Some grow in thickets, and others are vining climbers, but all sweet peas are lovely garden growers. Read on for a few sweet pea facts, as well as the information you need to start growing sweet peas in your garden this year.
What Is Sweet Pea?
Sweet peas belong to the genus Lathyrus. There are over 100 species of sweet peas and, according to The Southern Living Garden Book, “Despite the name, not all are fragrant. But all have the classic pea-family bloom—one large, upright, roundish petal (called the banner or standard), two narrow side petals (the wings), and two lower petals that form a boat-shaped structure (the keel).”
When Do Sweet Peas Bloom?
Sweet peas come in a variety of flowering types and forms, including heirloom selections, early-flowering sweet peas, spring-flowering sweet peas, and bush-type sweet peas. Early-flowering types bloom in midwinter and should be planted in October and November. Spring-flowering types should be planted from October to January. Bush types can thrive throughout the region and usually bloom in spring. Popular bush-type sweet peas include Bijou, Cupid, Jet Set, Knee-Hi, and Little Sweethearts.
What Kinds of Sweet Peas Should I Plant?
Popular sweet pea species to plant in the South include Lathyrus latifolius, or everlasting pea, and L. odoratus, known commonly as sweet pea. Heirloom selections, which are vine forms, include ‘America,’ which has scarlet blooms and white stripes; ‘Flora Norton,’ which has bright blue blooms; and ‘Indigo King,’ which has purple, maroon, and blue blossoms.
WATCH: 10 Plants You Should Always Prune in the Fall
How Do I Grow Sweet Peas?
Vine-form sweet peas will require a trellis or wire for support, while bush types should be planted in rows, spaced widely, and watered well. To start, according to The Southern Living Garden Book, “In less-than perfect soil, prepare ground for sweet peas like this: Dig a trench 1-1 ½ feet deep. Mix 1 part peat moss or other soil conditioner to 2 parts soil. As you mix, add in a complete fertilizer according to label directions. Back-fill trench with mix; plant seeds in it.” Sweet peas should also be regularly cut to prolong blooming period and tops should be pinched to ensure strong branching from the sides.
They’re a cinch to plant, and with a little attention, sweet peas will provide lovely blooms all season long. Will you plant some in your garden this year?
Balsam (busy Lizzie)
Impatiens (Impatiens walleriana) is regarded as an environmental weed in Queensland and New South Wales, and as a “sleeper weed” in other parts of Australia. This species has escaped cultivation and has often become naturalised in riparian areas and native bushland near habitation. It is probably most common in south-eastern Queensland, where it is ranked among the top 200 most invasive plant species.
Impatiens (Impatiens walleriana) is mainly naturalised in riparian habitats and other moist areas in south-eastern Queensland. It has also been recorded in Palmerston National Park in northern Queensland, where it has colonised forest margins and is also displacing native fern communities around waterfalls.
This species is also naturalised in bushland and around habitation in the coastal districts of New South Wales. It appears on several local and regional environmental weed lists in these parts of New South Wales (e.g. in Warringah Council, Pittwater Council, Lismore Council, the Sydney North region, the NSW North Coast region and the wider Sydney and Blue Mountains region) and has been recorded in some conservation areas throughout the eastern parts of the state (e.g. in Billinudgel Nature Reserve and Tunnel Gully Reserve). Impatiens (Impatiens walleriana) is also listed among the invasive weed species that threaten the integrity of particular stands of endangered littoral rainforest in New South Wales.
Touch-me-not Balsam pods explode without warning when they’re ready to disperse their seeds. The seed pods also happen to be the Netted Carpet Moth larva’s favorite food. So what happens when this hungry caterpillar eats from a pod that’s ready to pop? This BBC clip from The Lake District: A Wild Year, narrated by Bernard Cribbins, captures their challenge.
Some additional background from NationalTrust.org.uk:
Research has shown that this moth relies totally on touch-me-not balsam. This small delicate plant with yellow flowers is the only native species of balsam in the UK, but many invasive balsams are aggressively wiping this plant out. This means that the population of the netted carpet moth plummeted to near extinction in the 1980s and 1990s and has only recently begun to recover. The perfectly camouflaged larvae of this moth feed exclusively on the plant.
Numbers of this moth are returning thanks to a partnership of many organisations. Here in the south Lakes the National Trust ranger team has been working hard to play their part in the return of this species to many areas. By introducing cows to the favoured areas of the moth, research has shown that more aggressive plants such as Himalayan balsam are kept at bay, allowing the touch-me-not to flourish. Our rangers have also been “pulling up” invasive species such as yellow balsam to make space for touch-me-not to return.
Watch more exploding plants disperse their seeds with high pressure bursts.
Then watch more videos about seed dispersal, including this humidity-powered seed drills that itself into the ground.
Having Fun with Impatiens Seed Pods
One of my childhood favorite plants is Impatiens. Not only does it have beautiful flowers, but more importantly, it has explosive seed pods!
San Francisco Golden Gate Park Stow Lake
When wandering around in San Francisco Golden Gate Park during the pleasant summer days, I ran into a field of Impatiens. The soft yellow flowers caught my eye from a distance. I walked closer to check and confirmed it was Impatiens pallida. The most interesting part of this flower is the little hook-looking tail (spur) in the back. Having a spur is a very common trait in the balsam family (Balsaminaceae) flowers. As I recalled how much I loved the popping seed pods, I was excited and quickly looked for ripe seed pods. Luckily, there are plenty of them ready to pop!
Impatiens seed pods explode once touched. Hence, Impatiens has the common name, touch-me-not. By shooting those black seeds out, Impatiens gets a higher chance of dispersing its offspring. It is an shooting mechanism for reproduction.
I went after the big seed pods with black seeds inside. It was fun to lightly squeeze the seed pods to make them pop! Below is what the seed pod looks like after it has exploded.
If you would like to see those popping seed pods in action, I found a BBC YouTube video capturing those interesting footage. Below is the video.
This field of yellow Impatiens has become one of my favorite spots in San Francisco Golden Gate Park. You can see the field right next to Stow Lake on Strawberry Hill island. It’s a place that we get to have fun with nature like children again. If lucky, you may run into some cute ducklings and raccoons too!
Questions? Feel free to leave a comment below or reach me here.
Anemone likes living in a big city yet being close to the nature. She finds plants spark joy in people’s life and loves to share more about plants.
There’s Just Something About Sweet Peas!
Over the centuries, sweet peas have garnered the reputation of being the divas of the cottage garden: difficult to germinate, slightly finicky, and tough to grow. While there may be a grain of truth to this, sweet peas can still make a wonderful outdoor addition when the conditions are right.
Sweet peas (or Lathyrus odoratus) are native to Sicily and have been grown in gardens since the British horticulturist Henry Eckford began cross-breeding them in the 17th century. Since then, these plants have become famous for their delicate flowers, intoxicating scents, and pastel shades. Modern varieties are available in several colors, including white, blue, purple, red, and pink. Some sweet peas even feature beautiful bi-colored flowers. While some varieties only give off a subtle scent, most boast a full-bodied, sweet, and sensuous perfume that’s difficult to duplicate.
Why Plant Sweet Peas
While most plant enthusiasts would agree that sweet peas are beautiful, the special care required to start them from seed can be intimidating to new gardeners. Still, those who’ve made the effort will tell you that sweet peas have added color, fragrance, and overall visual interest to their gardens. Plus, they flower profusely, making it easy to create a ton of bouquets for you and your friends, family, and neighbors to enjoy! Sweet pea flowers continue to fill a room with their heavenly scent long after they’re cut — especially if you cut them in the morning when the aroma is at its strongest and sweetest.
Although they can technically grow anywhere, sweet peas tend to do better in places with cooler weather. Specifically, they prefer mild winters and cooler summers. Sweet pea seeds have to be sown in cool weather, and their flowers typically bloom right before the temperature starts to climb.
How to Grow Sweet Peas
Sweet peas are annual plants and will readily self-sow. The flowers go to seed if left uncut and form pods that vaguely resemble the pods of edible peas. While they are similarly shaped, sweet pea pods can be distinguished by their fine, white “hair.”
Unless you’ve saved seeds from the previous year’s flowers, you’ll likely have to purchase some from your favorite local or online seed retailer. If fragrance is one of your top priorities, consider growing heirloom varieties that bear a more traditional scent, such as Cupani (the original sweet pea) and Butterfly Old Spice. Painted Lady, a bi-colored variety, features pink and white flowers that emit a strong scent. If you’re looking for unique colors, check out Henry Eckford, Electric Blue, and Velvet Elegance, but remember that these varieties may not be as sweet-smelling as others. While sweet peas are great attention-stealers, they can also complement some of the showier blooms in your garden. For example, Dorothy Eckford is a sweet pea variety that produces subtle white flowers. Just imagine how they would look alongside some vibrant plants and flowers.
Sowing your sweet pea seeds will require a bit of preparation, but it’s more than worth it. Pre-soak the seeds for 24 hours, and nick the surface each one with a sharp blade. Although sweet peas are traditionally sown in the fall, people who live in colder climates (zone 7 or colder) might want to plant them in the late winter or early spring before the last frost. Sow the seeds in indoor pots to get them off to a great start before planting them outside. Be sure to harden the seedlings off for a week or so and place them in the garden when the soil is warm enough to work. When it comes time to plant, dig a trench about four inches deep and use a dibber or pencil to create small holes in which to drop the seeds.
In milder climates, you’ll want to plant sweet pea seeds in the fall. Although you’ll have to wait all winter to see your first blooms, your plants will have developed a strong root system and begin to explode with delicate flowers by the early spring. Flowers often last throughout the summer if you live in a cooler area like the Pacific Northwest, where I live.
Helping Your Sweet Peas Thrive
Regardless of when you sow, be sure to prepare the soil with compost or finished manure. Sweet peas need fertile, loamy, well-drained soil to thrive, as well as plenty of sunshine. You’ll also want to protect the seedlings from slugs, birds, and other pests that may see them as tasty treats. Create a barrier around them using cloches or the small plastic produce baskets from cherry tomatoes, berries, and strawberries you’ve purchased at the supermarket.
Sweet peas are vining plants that can grow up to 10 feet tall, so be sure to give them plenty of support using trellises, fences, arches, or bamboo stakes. If you prefer the plants to bush out, pinch the tops of their sprouts when they’re approximately six inches tall. Once flowers begin to appear, you’ll want to regularly deadhead the plants to encourage more blooms. The more you harvest, the more they’ll produce! However, sweet peas love cool weather and may start to produce fewer flowers when the temperature reaches above 70 degrees.
To keep your plants and flowers as healthy as possible, don’t let the soil dry out. While sweet peas don’t exactly like having “wet feet,” they definitely won’t grow well if the soil is dehydrated. To prevent this from happening, try planting some low-growing flowers or plants at the base of each sweet pea plant.
If you want to save a few seeds for next year, leave the flowers on the vine until they’ve had enough time to form seed pods. If the pods burst, they’ll often self-sow the following year. If you want more control over this process, simply collect the seed pods when they’re full.
Pests and Diseases to Watch Out For
Sweet peas can be damaged by a variety of pests, including caterpillars, aphids, and greenflies. The latter have even been known to spread mosaic virus. Pollen beetles can also create problems for sweet pea flowers, and, as mentioned above, slugs and snails can terrorize young seedlings. Sweet peas are also susceptible to diseases such as powdery mildew, Pythium root rot, gray mold, and rust. Luckily, you can prevent bug infestations and diseases by protecting your seedlings, watering them correctly, and promoting good air circulation as they continue to grow.
Sweet peas are beautiful and rewarding plants to include in your garden. Although they may need special attention when they’re young, the wonderful scent and bountiful bouquets they produce are worth the effort.
How To Grow Sweet Peas
- In warmer regions (zone 7 and above) where winter weather is relatively mild, sweet peas can be sown in fall. Everywhere else, sow in late winter/early spring. Soak the seeds in water for 8-10 hours before sowing. This softens the seed coat and speeds up the sprouting process.
- While the seeds are soaking, fill your planting pots with good quality potting soil. Sweet peas produce abundant roots, so use the deepest pots you can find. Root trainers and 4 inch pots are ideal.
- Sow 2 seeds per pot, poking them a half inch into the soil with your finger.
- Cover pots with a plastic dome lid to increase humidity and speed up germination. Place in a cool greenhouse, or in a bright window in the house.
- Once plant are 4-6 inches tall, pinch out the central growing tip, just above a leaf joint, leaving just two or three leaf nodes. This will encourage the plant to branch vigorously from the base.
- Sweet peas are heavy feeders and require a little extra pampering to produce abundantly. Prepare planting beds by applying bone meal, a thick layer of compost or well rotted manure and a generous dose of natural fertilizer. Mix these ingredients deeply into the soil.
- Vines grow rapidly and require a strong structure to climb. Place tall posts roughly 8 feet apart down the row and attach either Hortonova netting or 6 foot tall metal fencing for them to scramble up.
- Plant seedlings out around the last spring frost in two rows, one on either side of the trellis, roughly 8 inches apart down the row. As the vines explode into lush growth, it is important to keep them tied to their trellises. Once the vines get going, sweet peas can grow over a foot a week.
- Sweet peas love water, and without consistent moisture will fail to thrive. Keeping their thirst quenched during warm weather is crucial, so set up soaker hoses as soon as you plant them to keep their lush growth unchecked. Feed plants weekly with diluted fish and seaweed emulsion.
- For the longest vase life, pick when there are at least two unopened flowers at the tip of a stem. Add flower food to the water to extend vase life. To prolong blooming, it’s important that plants don’t set seed, so be sure to harvest and deadhead the flowers frequently.