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How to grow sweet peas

Sow your seeds in pots under cover in a bright spot during (very late) winter or early spring

By House & Garden | June 10, 2021 | Category

Image: Unsplash
Image: Unsplash

Sweet peas are the 1930s debutantes of the flower world. Their soft frilly blooms come in ball gown shades of cream, pink, soft blue and purple. Plunge your nose into a bunch and you feel like a drunken bee, hit with their heady honey-like fragrance. One of the nicest things about homegrown sweet peas is that they are an inexpensive. Here's how to grow them…

How to grow sweet peas

Sow your seeds

Sow your seeds in pots under cover in a bright spot between very late winter and early spring (where frosts occur). Sweet peas like to have plenty of space for their long roots so choose a deep pot or hoard loo rolls as these are the perfect size for sweet pea seedlings and can be neatly lined up on a tray, allowing each seed to have its own dedicated pot.

Pop your seeds about 1cm deep - depending on the size of your pot sow between 1-4 seeds, making sure they are at least 7cm apart so the delicate roots will not need to be prised apart when the time comes to plant them out. You can soak seeds overnight to rehydrate them and encourage but if you are impatient there's no need, just keep your compost well watered until they sprout. If you want to have sweet pea flowers from early spring until late summer it's worth planting two batches. The later batch could be sown directly into the soil if you haven't the space for many indoor seedlings.

To prevent your plants becoming leggy pinch off the growing tip after they have 3 or 4 pairs of leaves. This will encourage your plants to spread outwards as well as upwards, resulting in them being healthy and strong.

Build your supports

Build yourself a support - if planting in the border consider making wigwams with hazel sticks or purchasing a smart wooden or wrought iron obelisk which can be used year after year. Sweet peas also grow well over shallow archways. If growing in the vegetable garden opt for a larger structure, built from 8ft or 10ft bamboo poles - pairs of canes in a row, spaced 20cm apart and supported by a central tent-like top beam are ideal.

Plant out your seedlings

Once spring is on its way and frosty winter has passed plant out your sweet pea seedlings. Dig rich compost into the soil and plant two seedlings at the base of each cane or stick. At this stage you can also plant out some additional seeds directly into the ground. Keep a wary eye on the weather forecast and if temperatures are dropping again protect your plants from frost. Sheets of bubble wrap clipped to the growing frame with clothes pegs work well, as they provide plenty of insulation.

Sweet peas respond well to feeding, a potash-rich tomato feed works well or Sarah Raven sells comfrey pellets that are an excellent natural fertiliser. If you are lucky enough to have comfrey growing on your allotment you can brew yourself buckets of natural plant food, simply rip off 20-30 leaves, place in a bucket, fill this with water and allow to steep for 2 weeks or so. The mixture will smell and look fairly evil but it is liquid gold when it comes to feeding your plants!

Tie in your plants

Tie in your sweet pea plants as they grow, using soft garden twine - plants with a strong support will grow stronger, with straighter stems. You should aim to tie in straggly stems every 10 days or so.

Keep on picking

Sweet peas are true cut and come again plants. Once they start blooming keep on cutting them, once they set seed they think they've done their job and stop producing flowers. If you keep on cutting bunches of flowers you should end up with several months of sweetly-scented bliss.

Feature image: Unsplash

This originally appeared on House & Garden UK | Bonnie Robinson

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