Sweet peas are available in a wide variety of hues and designs. The majority will only reach a height of 5 or 6 feet, while shorter “bush type” variants are ideal for containers. Pick a few different varieties to extend the flowering season. Find types that bloom early (“short-day”) and late by reading the seed packs (“long day). Even though annual sweet peas predominate, perennial sweet peas are also available (Lathyrus latifolia).
Start early
It’s crucial to start sweet peas (Lathyrus odoratus) blossoming early so they can survive the summer heat because they like chilly temperatures. As soon as the soil can be handled in the spring, you can plant them outside. The seeds will likely be alright even though it will likely still be very chilly. Sweet peas can be planted in the south in late fall for late winter or early spring blossom. Consult local cooperative extension to learn about best practices in your community.
Start your peas inside for the longest blooming season possible. Timing is determined by the date of your region’s last frost. Back up the date by four to six weeks once you get it. You should then plant. For instance, you should plant in early to mid-April if your last frost date is May 15. Don’t know when your region last experienced frost? Consult local cooperative extension or a reliable gardener in the area.
Sweet peas can withstand how much cold?
According to Gardeners’ World (opens in new tab), sweet peas should be treated like any other non-hardy annual: “Plant your sweet peas outside starting in late May, after all danger of frost has passed. Put them outside throughout the day and bring them inside at night to harden them off before planting.
The most recent edition of Sarah Raven’s podcast (opens in new tab) claims, however, that “Sweet peas are hardy and can go in the garden from the middle of March.”
Confused? So were we up till we learned the RHS’s excellent sweetpea-growing tips (opens in new tab) (watch in the video above). Sweet peas are in fact “extremely tough,” says Propagation Leader Sam Gallivan, and they can withstand frosts “with no issue at all.” They do struggle with extended cold and rainy times, though. Your young sweet pea plants could perish if you reside in a region where early spring can bring both low temperatures just above freezing and a lot of rain.
Because of this, you have two options: either hold off and plant them outside in April when the weather will be warmer, even if it rains, or keep them in a cold frame until the chilly showers stop. However, sweet peas are typically categorized as half-hardy annuals and can withstand dry frost up to -4C. (25F). You will need to cover them with horticultural fleece in the event that temps fall below that.
Choosing sweet peas and perennial peas
The major consideration is whether or not aroma is crucial to you when deciding between perennial Lathyrus and sweet peas. Decide if you would then like an annual or perennial plant. There are several color choices available as well as climbing and bushier varieties.
Fragrance
Choose sweet peas (Lathyrus odoratus), which are generally very fragrant, if you enjoy a pleasant garden and sweet-smelling flowers for indoor use.
Lord Anson’s blue pea (Lathyrus nervosus), a perennial Lathyus, is an exception to the rule since it does have a perfume.
How long the plant lasts
After setting seed, sweet peas (Lathyrus odoratus) only have a one-year lifespan. However, don’t let this deter you because they are quite simple to grow from seed. Lathyrus latifolius is an example of a perennial species that returns every year, however there are fewer options and they typically lack smell.
Colour
The annual sweet pea (Lathyrus odoratus) has a large variety of blossom colors, including bicolored varieties. However, the perennial varieties do come in some uncommon colors, like yellow and orange.
Habit
The majority of Lathyrus are climbing plants, therefore support them with canes, netting, or allow them to climb over a bank or through a bush. For ground cover and pots, clumping varieties like the spring-flowering Lathyrus vernus and dwarf bushy sweet pea varieties like “Snoopea” and “Bijou Mixed” are excellent choices.
Buying sweet peas and perennial peas
The biggest selection of sweet pea seeds can be found from online seed supplier, though many garden centres also sell a few in packets. In the spring, several nurseries and garden centers sell pots of germinated sweet pea seedlings that can be divided into individual plants and raised in pots before being planted outside.
Seeds of perennial Lathyrus, such as Lathyrus latifolius, are available from a handful of seed specialists but many gardeners choose to acquire them as plants. The plant you’re looking for can be found using our Find a Plant tool.
When to plant sweet peas and perennial peas
- Annual sweet peas should be sown either in late January or early April and planted out in April.
- Sow perennial Lathyrus in the spring or the fall.
Where to plant sweet peas and perennial peas
Locate a sunny area where there is room for the plant to grow or to bush out (depending on its habit). Also acceptable is a little light shade, especially for Lathyrus grandiflorus.
How to plant sweet peas and perennial peas
- To avoid cold shock, indoor seedlings should be hardened off for 10–14 days before being transplanted outside.
- Ideally, four weeks before planting, enhance the soil by incorporating a soil conditioner like garden compost or manure.
- Sprinkle general-purpose fertilizer, as directed on the pack, into the area where you plan to plant it, such as Growmore, Vitax Q4, or blood, fish, and bones.
- Before planting, water your plants thoroughly to hydrate the roots.
- Remove pots from larger plants and ease seedlings out of modules or pots while being careful not to snap or crush the stems.
- Plants should be separated by 20–30 cm (8–1 ft).
- Place climbing plants near to their intended support (within 5-7.5cm or 2-3in), with two plants at the foot of each cane if they are climbing a wigwam.
- After planting, water once more to help the soil surrounding the roots settle.
Use garden twine or sweet pea support rings to secure young climbing plant shoots to canes, pea sticks, netting, trellis, or shrub shoots that they will be growing up. Tendrils in contact with supports will naturally start to cling on, but if any are straying or in danger of snapping, keep tying in new shoots.
In dry weather, check on plants in the ground every 3 to 4 days and on those in containers every day because they won’t flower as well if they become too dry. Each time you water, be sure to use enough water to completely moisten the roots.
Apply a high potassium liquid fertilizer, such as tomato feed, once or twice a week on light or infertile soils. This promotes flowering, particularly in annual sweet peas (Lathyrus odoratus).
Pick or remove dead flower heads as frequently as you can once flowering starts. For annual sweet peas (Lathyrus odoratus), which will stop flowering if seedpods are allowed to form, this is especially crucial.
Pinching out
When plants are around 7.5 to 10 cm tall, pinch out the shoot tips of new spring-sown sweet peas for gardening (3-4in). This promotes robust side branching. Autumn-planted seedlings frequently naturally branch.
Cordons
Pick the strongest shoot and keep pinching out all the tendrils and other sideshoots as they grow whether you want to enter your sweet peas in a local show or just want to maximize the size of blossoms for cutting. By using this technique, the plant directs its attention to the blossoms. The term “cordons” is used to describe these single-stemmed plants.
One stem per bamboo cane or tall stake needs to be tied to them on a regular basis. To keep the shoot in place as it grows, you can use twine looped in a figure-eight pattern around the cane and stem. Use sweet pea rings, which are wire loops that wrap around the stem and cane and are lightly squeezed until they hold, to make things simpler.
Cordons have the potential to grow much taller than the typical 2 m (6 1/2 ft) estimated height.
Cutting back
Cut perennial Lathyrus back to the ground in the fall, or better still, wait until February to do it so the dead stems can serve as wintertime cover for wildlife. When flowering is ended at the end of the summer, annual sweet peas can simply be pulled out and composted. This might happen a little bit sooner during hot, dry seasons.
Methods
Sweet peas can be immediately sown into the ground in April, or they can be planted in seed compost pots in the fall or spring. Although it takes more time, pot-sowing is typically more dependable than direct sowing. If you plant in the fall to enhance your chances of getting early blooms, keep seedlings in a coldframe or cold greenhouse over the winter to protect them from growing lanky. Keep the coldframe’s lid elevated unless a strong frost is anticipated. Sweet peas planted in the spring flower in 12–14 weeks.
Sweet pea seeds frequently have a tough outer covering that makes them more challenging to germinate. Place your seeds on a layer of damp vermiculite or kitchen tissue and store them in an airtight container in a warm area. As soon as the seeds swell or start to sprout, plant them. Some gardeners like to soak the seeds overnight instead, but if you don’t plant them right away thereafter, they might rot. With a sharp penknife, chip off a little portion of the hard seed coat to allow moisture to enter and promote germination on recalcitrant seeds that haven’t swelled.
- Individually sow seeds in seed compost-filled rootrainers or 9 cm (3 in) pots. As an alternative, sow five to seven seeds per 13 cm (5 in) pot, spacing them 2-3 cm (3/4-11/4 in) apart.
- Add 1 cm (1/2 in) of vermiculite or compost to the top of the seeds.
- Add water and maintain at around 15C. (59F)
- It is optional to cover the pots with clear polythene or glass to reduce the likelihood that they will dry out, but keep in mind to remove the covering after the seeds have germinated.
- Once they have grown to around 3.5 cm (11/2 in), carefully transplant single seedlings into 9cm (3 in) pots if you have seeded them several to a pot.
- Use your thumb and finger to pinch out (remove) the top of the shoot just above a healthy leaf when the seedlings are 7.5–10cm (3–4in) tall. This will promote side branches, which are always stronger than the core stem that has been removed.
- At least four weeks before planting, remove all weeds from the soil and add a soil enhancer, such as garden compost, manure, or composted bark.
- Only plant seeds as the soil begins to warm, typically around April.
- To create a wigwam, plant any temporary supports, like pea sticks or bamboo canes, in the ground.
- Take out a shallow drill of dirt 2.5 cm (1 in) deep for rows of sweet peas, and plant a seed every 5 to 7.5 cm in it (2-3in)
- Seedlings should eventually be spaced 20–30 cm (8–1 ft) apart to provide the plants enough room to flourish. The extra seedlings may seem like a waste to compost, but unless treated carefully, their roots are typically too damaged to recover.
- Push two seeds into the ground at the base of each cane to a depth of 2.5 cm (1 in) when sowing around a wigwam of canes.
Perennial peas
In the spring or the fall, divide bigger plants. If you want to divide Lathyrus vernus in the spring, wait until after flowering.
Unfortunately, very few of the issues with sweet peas and perennial peas are extremely problematic.
- Powdery mildew, which is brought on by drought or insufficient hydration, results in a grey leaf coating.
Do peas require frost protection?
Due to the plant’s growth tips being underground between the seed and the soil’s surface throughout the seedling stage, peas have excellent tolerance to frost. The plant’s nodes become active and will send a new shoot to the soil surface if a growth point is killed by frost. The pea plant won’t perish, but it will take longer to mature than it would have if its primary shoot hadn’t been harmed.
Sweet peas can they grow in pots?
It’s simple to grow sweet peas in pots! You may have colorful and fragrant sweet peas all summer long with a few easy tips and tricks!
Sweet peas thrive in containers and pots. They only require excellent soil, sunlight, water, and a climbing structure. After that, relax and watch your sweet peas, which have a lovely aroma, develop and prosper.
Easy to grow!
I’m a huge fan of sweet pea flowers. There may not be a flower with a more exquisite aroma, and their petals are so lovely and fragile. Since sweet peas are fortunately fairly simple to grow, I make sure to have a lot of them in my garden during the summer. Actually, you can have blooms well into the fall if you’re fortunate and the weather is nice.
Grow Sweet Peas in Pots!
My yard used to receive a lot of sun when we first moved into our house over 15 years ago, making planting sweet peas relatively simple. I used to plant them in a row along the back fence, but as our trees have grown, the location is now shady and no longer ideal for growing sweet peas. I now cultivate them in containers. I plant sweet peas exclusively in approximately 5 pots since I adore them so much.
Great for limited space!
You do not need acres of land to appreciate a garden, as I have come to realize over the years. You can grow plants if you have a balcony, patio, or small urban yard. Don’t let a lack of room prevent you from growing most plants because they thrive well in pots. In my teeny, small urban yard this summer, I actually planted a cut flower garden, and I loved it SO SO much. I’m going to plant more flowers this year!
Tips for Growing Sweet Peas:
I’ve learned a few things about cultivating sweet peas over the years, so I thought I’d share some advice I’ve received.
Look for dwarf or short kinds that don’t grow much taller than 2 feet. They are also referred to as bush sweet peas.
Actually, this is a matter of taste. As soon as the snow melts in the early spring, many people will sow sweet pea seeds immediately into their gardens, which is a fantastic time because the soil is damp enough to soften the seeds. I will occasionally do this, but I frequently forget to get them out in time, so I will soak the seeds first. This involves giving the seeds a 24-hour soak in water before planting them in the ground. The seed coat will become softer as a result, hastening the sprouting process.
Any pot or container you use should be at least 6 inches deep. The deeper the container, the better because sweet peas like to spread their roots out.
To ensure proper drainage, check the pots and containers you use for your sweet peas. Sweet peas dislike to stay submerged in water.
Use high-quality potting soil since sweet peas prefer rich soil. Compost should also be added to it as an amendment.
obey the directions on the package. However, the fundamental guidelines call for planting them 2 inches apart and 1 centimeter deep. Most of the time, I will sow more seeds than is advised in case some of them don’t germinate. Just thin them out if I get too many.
Because sweet peas like to climb, you should always give them something to do so. Sticks can be inserted into pots when utilizing pots so that when the sweet peas grow, their tendrils can cling to the sticks. In my pots, I simply used twigs; you can see them in the image above. A modest trellis or chicken wire are other options.
As they get higher, your sweet peas will require a little help. You may need to assist the tendrils so they will latch onto the stakes or trellis. I’ll use tiny pieces of thread to delicately attach the stems to the support rods.
Sweet peas thrive best when their roots are firmly planted in cold, wet soil and their blossoms are exposed to the sun. Consider adding some mulch to the pot once the plants have sprouted to maintain the health of their roots.
Sweet peas don’t actually require a lot of fertilization. Contrary to popular belief, sweet peas do not enjoy nitrogen as much as peas do. My sweet pea plants don’t get much fertilizer from me.
Keep your sweet peas well-hydrated without drowning them. They dislike getting too dry or damp.
It’s always so difficult to do this, but as soon as your sweet peas begin to grow, you need to pinch them back to encourage side shoots, which will produce strong, bushy plants. Simply use your fingers to pinch off the stem’s top just above a group of leaves to do this. I know it’s difficult, but your sweet peas will benefit from it.
Eliminate old seedpods and blooms. Doing this frequently promotes new growth, so be sure to do it!
If you’re anything like me, you grow sweet peas in order to harvest the flowers and bring them inside. The scent of them in the summer I just can’t get enough of. The good news is that when you select more blooms, more will grow as a result.
I hope this encourages you to plant sweet peas as well! You can have an abundance of lovely blooms all year long with a little care!