Sweet pea seeds should be directly put into the garden in the fall from September through November in mild winter settings where the ground does not freeze in order to develop robust root systems and blossom in the spring. If you are unable to plant your seeds in the fall, start as soon as spring arrives in a well-drained area that provides some afternoon shade.
In regions with difficult winters, plant about a month before the last date of frost after the worst of the weather has passed. If spring arrives early in your region and becomes hot and muggy, mulch seedlings well and place them where vines will have some afternoon shade.
1. Before planting, you could decide to nick your sweet pea seeds. The seed’s outer layer can be broken off by giving it a quick cut with a nail clipper so it can quickly absorb water. This will result in a higher percentage of your seeds germinating and a few days earlier sprouting.
This is how: Between your thumb and forefinger, hold a seed. Clip your seed by holding the clippers at an angle with the other hand so that you can only utilize the tip of the blade. Not taking a chunk out of the seed is your goal; it is to slice through the brown top layer of the seed. Sometimes the nick you caused is barely visible, and other times a bit of the seed coat cracks off revealing the interior seed’s lighter color. Both are true.
2. Since sweet peas require fertile, well-drained soil, add some aged manure or other finished compost to your garden bed before planting. Work the material into the soil and rake the bed to level it out. Make a furrow with a stick or a tool. Make sure your furrow is 1 inch deep since it’s crucial to plant seeds at the correct depth (for sweet peas, this is 1 inch).
3. When planting your seeds, space them 2-3 inches apart in your furrow. You have a better chance of getting a full bed of plants with no gaps if you sow your sweet peas at this spacing. You will thin your seeds later, when they have grown, to the desired spacing.
4. After sowing, fill in your furrow with earth to cover the seeds. You should only transfer enough soil to fill in the trench without building up a mound above the seeds since you want your seeds to be positioned one depth down.
5. Lightly mist the seeds you covered. To stop the water from washing away the soil, use a watering can or hose with an attachment that diffuses the water so that it showers gently like rain.
Tall sweet peas require a sturdy support in order to ascend. Build one now so that it is there when your seedlings are prepared to begin climbing.
6. You must keep birds, snails, and slugs away from your sweet pea seedlings. In order to prevent these typical predators from discovering your sprouts and eating them before you even realize they are up, you should do this as soon as possible after sowing your seed.
Use netting for birds. Using flexible, black plastic irrigation tubing, often known as polytube and sold at most garden centers, we create our own support hoops. It should be cut into lengths that correspond to the width of your garden beds. To create arches over your sweet pea bed, bury the ends of the cut tubing in the ground. These arches should be covered with bird netting, which should be secured at all edges to prevent openings. Before your sweet peas grow large enough to attach themselves to the netting, remove it.
We choose the product Sluggo for snails and slugs because it is safe for use on people, pets, and wildlife.
7. If you started your seeds indoors, the seedlings must be hardened off before being transplanted into your garden. Hardening off is the process of gradually exposing your plants to the elements they will experience outside, with temperature and direct sunlight being the most important factors. If you don’t, your seedlings can have transplant shock once they are planted in the garden.
When your plants have around 3–4 pairs of leaves, you can begin the hardening off procedure. Place your plants outside where they will receive morning sun in full force and afternoon shade. If you don’t have access to such a place, you will need to relocate your plants every day so that they are in the morning sun and out of the afternoon sun. Move them to a location where they will receive direct sun all day after about 3–4 days. You can move them into your garden in a few more days.
8. We advise deadheading to prolong the blooming period of your sweet pea plants. This entails removing wasted flowers before they have an opportunity to use their energy to produce seeds rather than other blossoms. Deadheading is best done right when the bloom has peaked and is just starting to fade. Cut the entire flower stem off at all times.
9. The blossoming on this plant is completely through. When you can see, the plants begin to slow down and eventually stop flowering altogether as the discarded blooms turn into seedpods. Whether you deadhead or not, all sweet pea plants eventually reach the end of their flowering season. However, you can extend the bloom time by removing spent blossoms.
10. The flowers are, of all, the whole idea of cultivating sweet peas. Remember to cut some and bring them inside; they make lovely, sweet-smelling bouquets. Additionally, the plant will produce more blossoms the more you cut!
How far underground should sweet pea seeds be sown?
To make a deep, narrow root run, some gardeners sow their seeds in toilet paper rolls.
Sweet peas are really simple to grow from seed. In the fall, you can sow them into compost pots and grow the young plants through the winter in a cold frame or chilly greenhouse. Alternatively, you can wait until spring to plant seeds in the ground or in pots.
The seeds should be prepared by leaving them on wet paper towels until they expand or sprout. The kitchen roll should be laid out in a sealed container and kept in a warm area. Although it expedites the process, moist soil will still allow your seeds to germinate successfully. In a pot, scatter a number of sweet pea seeds using high-quality compost. They should be buried about 1 cm deep, covered with compost, and well-watered.
Choose a tall container to give your sweet peas a strong start because they perform best when their roots are made to grow in a deep, narrow channel.
Before planting, should I soak the sweet pea seeds?
- Sweet peas can be seeded in the fall in warmer places (Zone 7 and above) where the winters are generally not too harsh. Other than that, plant seeds in late winter or early spring. Before planting, give the seeds a 24-hour soak in water. By doing so, the seed coat is softer and the sprouting process is accelerated.
- Fill your planting containers with high-quality potting soil while the seeds are soaking. Use the deepest pots you can find because sweet peas develop a lot of roots. Ideal containers are 4-inch (10-cm) pots and root trainers.
- In each container, plant two seeds by pressing a fingertip into the soil and a half-inch (1.25 cm) deep.
- To boost humidity and hasten germination, cover pots with a plastic dome covering. Place in a warm greenhouse or a house window with good light.
- Pinch out the center growth tip, just above a leaf joint, once plants are 4 to 6 inches (10 to 15 cm) tall, leaving just two or three leaf nodes. The plant will be encouraged to branch out strongly from the base as a result.
- Because they use a lot of food, sweet peas need a little more care to produce in large quantities. Apply bone meal, a thick layer of compost or well-rotted manure, and a generous amount of natural fertilizer to planting beds to prepare them. Incorporate these elements thoroughly into the soil.
- Vines require a sturdy foundation to climb and grow quickly. Affix Hortonova netting or 6-foot (1.8 m) tall metal fence to the tall poles spaced approximately 8 feet (2.4 m) apart down the row for them to climb.
- Around the time of the final spring frost, plant seedlings outdoors in two rows, one on either side of the trellis, spaced approximately 8 inches (20 cm) apart down the row. It’s crucial to keep the vines bound to their supports as they erupt into lush growth. Sweet peas can grow more than a foot (30.5 cm) per week once the vines begin going.
- Sweet peas adore water, and they can’t survive without regular watering. Set up soaker hoses as soon as you plant them to prevent their luxuriant development from being restrained. It’s important to maintain their thirst quenched during warm weather. Use diluted fish and seaweed emulsion to feed plants once a week.
- Pick flowers when there are at least two unopened blooms remaining on the stem for the greatest vase life. To extend the life of the vase, add flower food to the water. It’s crucial to prevent plants from going to seed in order to prolong blooming, so be sure to regularly harvest and deadhead the flowers.