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.
Must I remove the sweet pea seedlings’ pincers?
Sweet peas should be planted in a well-drained but moisture-retentive soil in an open, sunny location. Sweet peas are ideal for container gardening. utilize a compost that is good, peat-free, and has a slow-release fertilizer added in.
How to sow sweet peas
From seeds, sweet peas are simple to grow in the spring or autumn. If you are planting in the fall, make sure you have space for them to grow until spring in a frost-free location.
Sweet pea seeds sprout fairly quickly. However, by nicking the seed coat with a knife and avoiding the “eye” region, you can encourage germination. Either plant seed in trays, root trainers, or 9cm pots (3 to a pot). Place the seed in a cold frame or greenhouse after sowing it in high-quality, peat-free compost.
View Monty Don’s instructional video on how to cultivate sweet peas from seed:
Planting out sweet peas
Once all risk of frost has passed, you can start planting your sweet peas in late May. Put them outside throughout the day and bring them inside at night to harden them off before planting. When young sweet pea plants are around 10 cm tall, pinch out the tips to promote bushy growth.
In the spring, you can purchase sweet pea plug plants. Under a support, such as a wigwam made of bamboo canes, plant them in rich soil. The average sweet pea will reach a height of 2 meters. Until they have a healthy growth, water them well. Don’t worry about separating individual plants; simply space sweet pea plugs or pots about 20 cm apart.
Watch Monty as he demonstrates how to put out store-bought plants while planting sweet peas. Find out the advantages of giving them a nice drink after planting as well as why it is best to plant them out just once the soil has warmed up:
How much water do sweet pea seedlings require?
Rarely do sweet peas require more than once a week of watering, but you must keep an even moisture level throughout the growing season. They dislike the heat, so water them frequently during the summer, but do it early in the day to prevent buds from dropping, plants from scorching, and to yield fewer flowers. To irrigate their roots, it is preferable to utilize drip or furrow irrigation rather than overhead sprinklers, which can cause fungal diseases in the vines.
How are sweet pea seedlings transplanted?
When to Plant: Sweet peas can withstand light frosts, therefore in cold winter regions, sow in seed starting pots in early spring approximately 6-7 weeks before the final day of frost. Then, plant out as soon as the soil can be handled.
Sweet pea seeds can be directly placed into the garden in the fall from September to November in mild winter settings where the ground does not freeze. This will allow the seeds to develop healthy root systems and bloom in the spring.
If you give your seeds a head start by sowing indoors in seed containers from late January through March and transplant into the garden as soon as the soil can be worked, you can still receive a decent harvest of sweet peas, even though they will bloom a bit later. Sweet peas can handle light frosts.
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. Avoid using garden soil when planting sweet peas in containers. Use high-quality potting mix instead. Using garden soil can lead to issues like compaction and poor drainage, whereas potting mix recipes are designed to perform under the circumstances found in a small container. In garden centers, a variety of soil mix brands are easily accessible.
Before filling your container, always pre-moisten your potting mix. As you slowly pour water into a bucket or wheelbarrow and stir the dirt, the earth will become evenly moist. When it feels like a wrung-out sponge, you are finished.
A 3 to 4 inch container works well for starting sweet peas. To prevent spreading disease to your new soil mix, properly clean the pot before using it again. After adding the pre-moistened mixture to the pot, give it a quick tap on the work surface to settle the soil. When a pot is filled correctly, the soil surface will be about 1 inch below the container’s top.
3. The time has come to plant your seeds. It matters how deeply you plant them. Always adhere to the planting depth recommendations on your packet’s back. Make a hole that is 1 deep for sweet peas. For this, a pencil or your finger works great.
4. Insert the seed into the opening you created. In order to ensure that every pot eventually gets a plant, even if one seed does not germinate or dies, we advise sowing two seeds each pot.
If you decide to plant 2 seeds per pot, you will need to thin them after the first set of leaves appear to 1 seedling per pot. At the soil line, trim or pinch out any surplus seedlings. Pulling it out could damage the surviving seedling’s roots, so avoid doing so.
5. Cover your seed with soil mixture after sowing. To remember what you planted when and how much of it, we advise labeling your containers with the variety and the date.
6. Lightly mist the seeds you covered. Use a watering can or hose with a diffuser attachment to let the water fall gently like rain. This will stop the water from washing the dirt away or compacting the soil too much.
Create the ideal circumstances for germination as you wait for your seedlings to appear. The two most critical variables are water and temperature. Your soil should always be damp, but not drenched. The ideal soil temperature is between 55 and 70 °F. You can start your seeds outside if the weather permits. A greenhouse or your home must be used to start them otherwise. Provide protection from birds, snails, and slugs if beginning them outside.
You must give your seeds a decent source of light once they have sprouted. If you want to keep them inside, you can put them beside a window as long as the sun won’t make them too hot during the day. Sweet peas do not have an issue with cooler nighttime temperatures near a window. Another option is fluorescent lighting. However, for the intensity to be bright enough, plants should be placed between 6 and 12 inches from the lights.
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. You can pinch or chop off the top of your seedlings when they have 3–4 pairs of leaves, leaving 2-3 pairs of leaves. Your cut should be made just above two leaves. By encouraging lateral branching, pinching helps you grow plants that are fuller.
9. Since sweet peas require healthy, well-drained soil, add some aged manure or other finished compost into your garden bed before planting. Work the material into the soil and rake the bed to level it out.
To move your seedling, make a hole that is both deep and wide enough to accommodate the root ball.
10. Try to minimize root disturbance while transferring your sweet pea seedlings from their container. Try it. Put one hand over the top of the pot, the seedling in your fingers, and flip the pot over to grab the root ball. Using the other hand, gently touch the bottom of the container while squeezing the edges to release the soil and plant.
11. Insert your seedling into the resulting hole, then cover it with soil. It is crucial when transplanting sweet peas that the soil level remain the same as it was in the pot. The plants may become sickly, stunted, or even die if you bury too much of the stem.
12. Leave 5 to 6 feet between each transplant. Your mature sweet peas’ health depends on the proper spacing between plants. Additionally, it provides the roots of individual plants with enough room to forage for water and nutrients while also enhancing air circulation to help avoid disease.
13. Gently water in your seedlings as soon as you are done transplanting. In addition to giving the plant water, this settles the garden soil around the root ball to prevent huge air pockets from drying out the roots. Use a watering can or hose with a diffuser attachment to water your plants, which will make the water fall gently like rain instead of washing the dirt away or beating your tender seedlings.
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.
14. 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. We create our own support hoops out of polytube, which is a flexible, black plastic irrigation tube that is sold at most reputable garden centers. 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.
15. You might want to assist stray branches in locating their vertical support structure as your plants grow higher and begin to climb. Encourage them to cling to you gently. Branches of sweet peas quickly break.
16. 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.
17. The blossoming of this plant is fully complete. 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.
18. The flowers are, of all, the whole reason of producing sweet peas. Don’t forget to frequently clip them and bring them inside. They create lovely bouquets with the most amazing scents. Additionally, the plant will produce more blossoms the more you cut!
How are lanky sweet pea seedlings fixed?
A 50p package of sweet pea seeds was one of my achievements from the previous year. Despite their modesty, they transformed the garden, the allotment, and whatever windowsill I could find to place tiny jam jars filled with freshly picked flowers.
Sweet peas require some heat to germinate.
A cozy windowsill will do. The ideal time to plant is six to eight weeks before the last frost, making the present almost ideal. Wait until the earth has warmed up at least by mid-spring if you miss this opportunity. Both are good strategies, but by sowing now, you can harvest later.
After a warm start, they must be grown hard in a cold frame, an unheated greenhouse, or a porch; if the nighttime temperature drops below -5°C, however, cover them with a thin layer of fleece. Give them enough light for them to become strong and upright, and that’s it. You will get weak plants if you cosset them in any way.
Don’t bother soaking seed or nicking the seed coat—both actions might cause more harm than good. Instead, pay attention to the pot. Sweet peas prefer a deep root system. You can recycle toilet paper tubes, newspaper that has been folded into a pot, or long food containers in instead of purchasing root trainers, which are long hinged plastic pots that fit into seed trays (Pringles pots work a treat). Kick your seedlings outside into cooler conditions once they have four genuine leaves. Your seedlings will naturally sprout side shoots if you cultivate them vigorously. When you have four or more true leaves, prune the top two leaves to promote bushy development if you see your growth is lanky.
They are prepared to plant outdoors on a bright day in late March for those in the south and sometime in April for those further north, once the threat of frost has passed. Fill the planting hole with a sizable amount of homemade compost or well-rotted manure. The key is to get those roots down as far into the ground as you can, and then mulch to keep moisture in and reduce water use. Birds, mice, and slugs are all annoying at times. Try to net, trap, and dissuade as much as you can.
Sweat peas can be grown in pots, but choose dwarf kinds and keep in mind that they are thirsty and hungry plants. In fact, choosing which sweet pea type to grow is nearly as difficult as actually cultivating the plants. The bicolor heirlooms “Cupani” (maroon and violet) and “Painted Lady” (white and pink) are dependable and have a wonderful scent for beginners. Thompson & Morgan’s “Heirloom Bicolor Mixed,” which was last year’s 50 pack, is a variety I’d happily grow once more, while a glance through Roger Parsons’ catalog (rpsweetpeas.co.uk) would have you daydreaming about giving the whole garden over to these stunning plants.