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Growing sweet peas from seed

Lisa Garden on 28-11-2017

Many gardeners grow plants from seeds, and specifically sweet peas are one of the most popular annual flowers grown in the UK. They have beautiful blooms, that are ideal for bringing colour and fragrance into your home during their long flowering season. Sweet peas have been cultivated for over 300 years and are native to Sicily. There they have weaker stems and delicious, orange jasmine scented, colourful flowers. 

When should I set seeds if I want to grow sweet peas in my garden?

Sweetpea seeds may be grown in the spring but you will have better plants if you start them off in the autumn and leave the young plants outside in a cold frame or an unheated greenhouse. Sweetpea seeds have a hard outer coating but trials have shown that they germinate better without soaking. Expert sweet pea growers recommend planting seeds in root trainers or toilet rolls to encourage strong root growth. Use a good seed compost, sow the seeds 1cm deep and water well. Sweet peas do not need to be watered again until you see the small shoots coming through, usually in 10 – 14 days.

Mollycoddling is a mistake that gardeners who grow sweet peas often make

When you are growing sweet peas it is important to leave them out in the cold as heat can inhibit germination. Sweet peas can tolerate temperatures of -10 degrees and frost seem to do them good. Once they are established they will need to be pinched out by removing the growing tip to encourage side growth. While you are waiting for your sweet peas to grow you can make some frames for them to grow up. You can use a teepee made from canes, sticks or wood and netting to give them the support that they need.

Once sweet peas have grown 2 – 3 inches tall you can plant them out in the spring

For sweet peas to grow well they will need a nice sunny or dappled shady spot in the garden. You should plant the sweet peas 20 – 30 inches apart at the base of your frame. In the hole for planting, you should add some manure and then cover it with a few inches of soil before setting the plant. Water the plants well and if your soil is not very rich then sweet peas will benefit from a potassium-rich fertiliser bi-weekly. 

Growing sweet peas will supply you with cut flowers for your home

While your sweet peas are growing they will benefit from a good covering of mulch to retain moisture and attract ground feeding birds who will visit your sweet peas to catch slugs and worms.
The more you cut the sweet pea flowers, the more blooms plants will produce, do not let them produce seed pods or their work will be over. Your local garden centre will be able to provide you with the correct feed and growing compost and they will have many sweet pea seed varieties for you to choose from. If you haven't bothered sowing beautiful sweet pea seeds then you can buy young plants from your local garden centre and still enjoy these delightful flowers.