When the plants are about 6 inches (15 cm) tall, pinch out the developing tips to promote bushiness and lateral growth. Mulch the plants now might be a good idea as well.
Applying water gently and deeply, water the soil surrounding the plants often enough to keep it moist.
Twice during the growing season, fertilize with liquid fertilizer at half intensity. A surplus of foliage is promoted by excessive fertilizer at the expense of sweet pea blooms. To promote new blooms, remove discarded flowers.
Warning: Although sweet pea seeds resemble edible sweet peas, they are poisonous if consumed. Make sure kids who are assisting in the garden don’t put the tools in their mouths.
Do my sweet peas need to be pruned back?
I have a beautiful sweet pea vine that has grown up the chain link fence and is covered in many pink and white blossoms. What maintenance should I give it over the winter? Must the vine be removed from the fence?
Although there are annual forms, perennial sweet peas are hardy in zones 4 to 8 and require little assistance to survive the winter in these regions. To boost hardiness, leave healthy plants standing over the winter. Before the plants start to grow, prune them back to the ground in late winter or early spring. In the fall, cut back sickly sweet pea plants to the ground. To lessen the chance of more disease issues, throw away the leaves and stems of sick plants rather than composting them.
How are sweet peas kept in good health?
In a sunny location, sow your seedlings in March and April. Sweet peas prefer well-drained soil, but because they are such hungry plants, it’s a good idea to add manure or garden compost to your soil to improve it.
Along with giving your plant food, it will also aid in the soil’s ability to retain moisture, which your sweet peas will appreciate. Select dwarf types and a deep pot to allow enough room for roots if they are going into a balcony or smaller area. To aid with drainage, put some rocks or crocs at the bottom of the pot.
Your sweet peas should be planted out 5 cm away from the support, with preferably at least 20 cm between each plant. This will allow for some air circulation and ensure that they aren’t fighting over food. Make careful to give your sweet peas plenty of water after planting.
If slugs are a problem in your yard, you can use sharp sand to surround the seedlings. It’s also a good idea to bury a few small twigs next to the seedlings to scare off any hungry birds.
Tie your sweet peas to the support as they begin to develop; as they get taller and taller, this will become a fortnightly task. I like to give mine a regular dose of organic liquid seaweed feed, though comfrey might also be effective. Water them frequently in dry weather to keep them healthy, and daily cuttings once they begin to bloom will help you get the most out of your sweet peas.
Until the end of the summer, when you can let them dry and save for sowing the following year, keep an eye out for any seed pods that develop and cut them off.
spring
- From March to May, you can easily plant your young sweet pea plants outside. Before planting out, sweet pea seeds sown in the winter or autumn need to be potted up into larger containers. Spring-sown seeds can be transplanted from their rootrainers.
summer
- Pick your sweet peas and arrange them in vases indoors. Remove the seed pods from your sweet peas to continue deadheading them. You’ll need to harvest and deadhead them frequently when they’re at their height.
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.
Prepare your ground
It is crucial to prepare the ground. Early in the year, make a deep soil excavation and add a decent all-purpose base fertilizer. The optimal time to add organic material and well-rotted manure is in the previous autumn. In the spring, if you mix too much, you can end up with more stems and leaves than blooms.
Put up a good support.
Ideal supports for plants to climb up are sturdy canes or hazel poles that are 2 meters (6 feet) in height. You need a sturdy, stable structure that gives the plants on all sides access to direct sunshine. In the shadow, sweet peas do not do well.
Always sow sweet pea seeds in deep pots or tubes
If the plants are to grow successfully, they must build a long tap-root system. Make sure you can transplant without harming the roots no matter what you choose to use. From April on, you can seed directly into the open ground, although few areas have soil that produces the best crops when grown this manner.
Planting out
Seedlings should be planted out as soon as they are big enough (about 5 cm, 2 in) and should be protected from birds, slugs, and snails. Sweet peas are quite hardy and benefit from chilly soil to develop more effectively. Too much time spent indoors weakens the plants and draws them in.
Tying sweet peas
As the plants begin to grow, carefully secure them to the canes or poles with flexi-tie (that flexible plastic tie) or soft string. Sweet pea rings made of delicate wire can also be used. Avoid damaging or breaking the stems.
Cutting back tendrils
Although it is not necessary to cut the tendrils, doing so keeps them from tangling with one another and the flower stems. Flower stems that have tendrils wrapped around them become bent and curled, making them unusable for cutting.
Watering is essential.
Bud drop and stems devoid of flowers are the results of dry soil at the roots during bud formation. This typically occurs at the start of the growing season when there has been some precipitation and the grower assumes that the soil is sufficiently moist; it frequently isn’t.
8. Continue to cut flowers
Continue pruning as the blooms bloom to encourage more blossom production. Never allow seeds to mature on plants. Sweet peas should be considered an annual. If seeds grow, they signal to the plant that its task is complete, and the plant begins to wither.
Feed your sweet peas
Feed with a general liquid fertilizer as soon as the plants begin to grow after planting out and throughout the growth season. Ideal fertilizers include those made for summer bedding plants or tomatoes. Dried Blood was my mother’s recipe for success, and it always seemed to work. Organic gardeners might want to give it a try.
Extend your sweet pea growing season
Keep in mind that sweet peas were historically planted in the fall outside in cold frames or unheated greenhouses. This means that the plants can be planted out early the next spring to give you earlier flowers because they are well-developed. For a longer flowering season, it’s worth growing half this way and half from a spring sowing.
So which varieties will I be growing?
I was overjoyed to discover “Wiltshire Ripple” among Suttons Seeds’ offerings. This was growing alongside the wonderful deep maroon “Beaujolais” in Harlow Carr, and the two were magnificent together. I also like Suttons Seeds’ “True Fragrance,” a frilled and flecked blend.
I especially adore the heirloom sweet pea variety “Prince of Orange,” which contrasts nicely with the deep purple-blue “Cupani.” Try Sweet Pea ‘Juanita’, a vibrantly colored combination of some of these strongly scented blooms, if you enjoy the notion of these fragrant Heirloom variety.
Last but not least, “Noel Sutton” is essential to me for it to be sweet pea time. The ideal Sweet Pea is this large-flowered, frilled, fragrant, soft blue kind; it is everything you would want in a flower of this caliber.