Top tips for growing sweetly scented sweet peas. Includes how to sow seeds, growing sweet peas in containers, and choosing the right sweet pea variety for your garden.
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Growing sweet peas isn’t difficult but they do need the right soil, care, and support. Very popular in Britain, sweet peas are becoming much more known in other parts of the world as a fragrant flower for bouquets. They’re so much more than that though since they look as lovely in the garden as they smell in a vase. Growing up handmade wigwams or around the front door, their simple and colorful blossoms attract pollinators and smell incredible. Better yet, the more you pick sweet peas, the more they produce flowers. A freshly picked bouquet can last around five days and add instant natural fragrance to your home. By the time the bouquet needs refreshing, many more blossoms will have bloomed and are ready for the next bouquet.
Sweet peas are temperate climate garden flowers. That means that they love warm, but not hot, summer temperatures and plenty of rain. However, rain you can compensate for this by regular watering, and warmth can be controlled to some degree by where you plant them. If you’ve not grown sweet peas before, here are six tips to get you started.
1. Choose the right Sweet Pea Varieties
There is a dazzling array of sweet peas available and seed catalogs can be dominated by them! That means that choosing the right type can be both exciting and a little daunting. First of all, sweet peas are not the same as edible garden peas and come in two types — the scented and annual-growing Lathyrus odoratus and the unscented and perennial Lathyrus latifolius. The latter looks very similar to scented sweet peas but literally smells of nothing.
The sweet peas that I grow, and that I’m sure you’re here to learn more about is Lathyrus odoratus. Within that species, there are many types of sweet peas bred for different colored blossoms, styles of blossoms, sizes of blossoms, and growing habits. There are even sweet peas that change color! Each sweet pea group will also have many varieties to choose from. The sweet pea variety is generally the most prominent name on the seed packet and is the name that most gardeners will know it by. The two main groups of sweet peas are:
- Grandiflora sweet peas, also called antique or heirloom sweet peas, typically grow up to seven feet tall. They have shorter stems and a lot more fragrance than modern varieties. Look for ‘Painted Lady’ and ‘Matucana’
- Spencer sweet peas, growing up to ten feet, with long stems, and a wide range of scents. They’re also more heat-tolerant so might be an option if your summers get hot. This is the type most commonly grown for the show bench and popular varieties include ‘Lipstick’ and ‘Windsor’
2. Sowing Sweet Pea Seeds
Sow sweet peas seeds into small pots or modules, rather than directly in the ground. Soak the seeds overnight, and place 1-2 seeds per pot about 1/2″ deep in multipurpose potting mix. Modules will give you more success since you can keep an eye on the seedlings in their early days. Keeping them safe from cold weather, deluge and pests are much easier done when you can lift them out of harm’s way. Sweet peas, like garden peas, will appreciate a deeper growing space since their roots grow deep, relative to their size. Although ordinary modules or pots will do, sowing seeds into deeper root trainers or toilet paper rolls can encourage stronger growth.
More Flower Gardening Ideas
Sow sweet pea seeds either in autumn to winter and overwinter the small plants in an unheated greenhouse or cold frame. Many British gardeners (zone 8) sow their seeds in early autumn and leave the plants in the greenhouse all winter long. The mild winter temperatures keep the plants from growing too much, but they begin to shoot up again once it begins to warm.
If you want to start sweet peas during the winter, you’ll need to do it on a heat mat or inside the house. The sown seeds need to be kept around 10-15C (50-60F) in order to germinate. After you see green sprouts, move the modules to a place that’s kept at 5-10C (40-50F) both day and night. This slows them down so that they don’t grow too large before spring. You can also wait to sow seeds in spring, but the plants and blooms may take longer to grow.
3. Pinch out the Growing Tips
Sweet pea plants are naturally tall single-stemmed climbers. However, if you pinch off the top growing tip of the plant when it’s young, it encourages side shoots and a thicker and more blossom-abundant plant. It’s a trick that will give you masses of sweet pea flowers and doesn’t hurt the plant at all.
What you do is wait until the plants are about 4-6″ tall. Then with a pair of snips or your fingernails, pinch out the top part of the plant just above the first set of leaves. This stops upward growth temporarily, and the plant will focus on creating side shoots. It’s these new shoots that will continue growing upwards and give you double or more flowers per plant.
4. Grow Sweet Peas in the Garden or Containers
Sweet peas need vertical space to grow but are flexible about where you have them planted. That means that you can plant them in your cottage garden, or plant them in large containers. If you keep a container near the door you’re greeted with a beautiful scent every time you leave and enter the house. What a great way to begin the day.
Either way, space plants about 8″ apart and into rich soil or potting mix. Soil rich in compost and aged manure encourages lush green growth. Adding a sprinkling of bone meal encourages root growth and potassium-rich feeds and fertilizers encourage bountiful blossoms. Also, ensure that sweet peas are kept well watered or they’ll have a tendency to die back and produce fewer blooms.
5. Growing Sweet Peas on Supports
Sweet peas are fast climbers and given the right conditions, can easily grow six feet tall. What this means is that you should grow sweet peas on supports, and keep tying the plants to the supports every week as they’re growing. Tying them in with pieces of soft garden twine keeps the stems from falling down and breaking. As for supports, I’ve seen gardeners growing sweet peas on ordinary garden pea netting, on lattices, on wigwams, up trellises, and over willow arches. Feel free to get creative with how you grow your sweet peas. You could even use recycled materials to save money and add character to your growing space.
6. Grow Sweet Peas for Cut Flowers
Though of course, sweet peas look incredible clambering up rustic trellises, you need to pick the flowers to keep them producing flowers. If you don’t, then the flowers will set seed and the plants will die back. That’s great news since you can get an ornamental flower and cut flowers in one. They’re honestly my favorite cut flower and I love keeping a bouquet on my bedside table. Waking up to their sweet scent can’t help but put a smile on your face.
To pick sweet pea flowers, use a pair of scissors, and make a cut at the base of each stem. Run your fingers from the flower downwards and make a cut just above where the stem meets the main plant. Gather a handful and make sure to get them in a vase of water as soon as possible. After cutting, the plant puts more effort into creating new flowers since what it really wants is for its flowers to turn into seeds for the next generation. That means that the more you pick, the more flowers you’ll have for both the home and blooming in the garden.