One of the best plants for cutting, sweet peas (officially known as Lathyrus odoratus) offer tempting colors and aroma for spring and early summer bouquets. The tiny flowers emit a grape-like fragrance into the air and come in a variety of beautiful colors. We enlisted the assistance of Barb Pierson, our nursery manager, to provide some guidance for individuals who have never grown Sweet Peas in a garden or a container pot. Any beginner or green thumb can benefit from a plentiful supply of these lovely flowers thanks to her advice.
Why do people grow Sweet Peas?
Sweet peas are cultivated for their lovely, ruffled blossoms, which come in pastel, blue, and bicolor hues. They are a beautiful cut flower since many types have scented blooms. The cultivation and breeding of sweet peas for both the home grower and the florist industry has a long history.
How do I go about growing Sweet Peas?
Sweet peas can be grown from seed that is treated before sowing or, more conveniently, from a starting plant. At White Flower Farm, we plant three seeds in each pot to create three Sweet Pea vines.
Where do I plant them and when?
In the northern half of the US, sweet peas flourish in the full sun. They can benefit from afternoon shade in the South. They are planted as early as possible in the spring since they prefer mild temperatures and cool roots. Newly planted seedlings will not be harmed by a mild cold. They can be sown in the fall and cultivated through the winter and early spring in highly warm climates. Compost should be added to the soil, and the area should be well-drained for optimal results. Sweet peas can be successfully grown in raised beds.
Do they need any special care while they are growing?
Sweet peas require support to grow and flower because they are climbing plants. Many other kinds of structures, like a trellis, supports made of mesh or wire, or fences, can be used. To sustain the weight of the vines, they require a sturdy framework that is firmly planted in the ground. The vegetation will develop tendrils that encircle the support you offer.
Since they like nutrient-rich soil, adding compost at planting time is advised. Mulching Sweet Peas will keep the roots cool and help them retain moisture as they grow.
Pinch the growth tips by one after the plants have reached a height of around six to encourage branching and the development of extra flowering stems.
What are the most common mistakes that people make with Sweet Peas?
- planting them in the middle of the summer They dislike the heat and won’t blossom as frequently.
- not offering assistance when planting. Once the plants have begun to grow, it is challenging to install your trellis or support.
- Lack of compost or fertilizer will cause weak plants and fewer flowers in poor soil.
- If Sweet Peas are planted too closely together without being thinned out, powdery mildew can grow and crowding lowers bloom production.
Do Sweet Peas produce pods that you can eat like the ones you find in the grocery store?
Despite having the appearance of snap pea pods, the seed pods are not edible. The pods and seeds can be saved in order to grow plants the following year. Remember that the plants that the seeds may grow may not be the same hue as the parent plant.
Will the plants come back again next year?
The plants are typically not winter hardy in most areas. They are replanted with new seed and plants even in warm climates to produce the most flowers and have robust development.
When do they bloom? Are there tips for getting extra blossoms?
Sweet peas will begin to blossom 4 to 6 weeks after they begin to show apparent vining. Whether or not the plants have been pulled back will affect the timing of the bloom. Although pinching may slightly limit growth, it will result in bushier plants with more flowers. In the spring and early summer, sweet peas will grow and bloom more quickly as the days lengthen. Compost or old dry manure can aid to supply nutrients for the growth of huge, many blooms. A fertilizer with a phosphorus to nitrogen ratio greater than one can also increase flower production.
What is the process for cutting the blooms?
Cut the blossoms early in the day to prevent the sun from drying them off. For your vase, select newly opened flowers with the longest stems. Just the side flowering stems of the plant should be clipped; leave the main stem alone.
Why should I get my Sweet Peas from White Flower Farm?
No seed treatment or waiting for germination is necessary because our plants are grown in our greenhouses in the spring and supplied to you at the ideal time for planting in your region. Our sweet peas arrive completely rooted and ready to plant in the ground in 4 pots, each containing 3 seedlings. You can avoid the time and hassle of starting sweet peas from seed by doing this. The quickest method to enjoy these beautiful flowers outdoors and in vases within your house is to purchase and plant our Sweet Pea seedlings.
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
Although many garden centers also sell a few sweet pea seeds in packets, the largest assortment of sweet pea seeds may be acquired from internet seed suppliers. 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.
There are a few seed specialists who sell perennial Lathyrus seeds, like Lathyrus latifolius, but many gardeners opt to purchase the plants instead. 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.
How are sweet peas made to bloom?
Why aren’t sweet pea blooms blooming? This occurs for a number of reasons. Here are some potential causes to check for in your plant to determine the exact cause:
How much light are your sweet peas receiving? Sweet peas require six to eight hours a day of direct sunlight. The quality of the plants’ flowers improves with more light. Regarding light, they favor long days. 16 hours should make up the perfect day, followed by 8 hours of darkness. Although the duration of the day is not essential, keep in mind that they might not perform at their very best without long days.
Do you fertilize them properly? They only truly require a small amount of compost, and if you are growing them in rich soil, they won’t even want that. If they receive an excessive amount of nitrogen, they develop lush green foliage instead of blooms. On the other hand, phosphorus promotes the growth of flowers. Keep lawn fertilizer away from your sweet peas since it contains a lot of nitrogen.
Are your sweet peas being deadheaded? In order to prevent the plant from producing a seed pod, blossoms should be removed as soon as they start to fade. If the plants produce pods, flowering is slowed and may even stop. You don’t need to keep an eye on them all the time, but you should go check on them every few days to take the spent blossoms off. You might discover that you like doing the work. Bring your pruners so you can collect some blooms to enjoy inside.