Growing Sweet Peas
How to Grow Sweet Peas
Sweet Peas, latin name Lathyrus odoratus, look just fantastic as the images above show but even better they are one of the most sweetly scented of garden plants. Sweet peas are long flowering and provide colour, scent and flowers to pick for months. Sweet peas are not difficult to grow but they need regular attention throughout the summer by dead heading, removing tendrils and watering during dry spells, which is why they are tagged with a red wheelbarrow. Sweet peas are rewarding for their fantastic scented flowers. The down side to growing sweet peas is they are time consuming, and Colour Coded red. The most important task is to dead head the flowers as they fade and form seed heads, this ensures the Sweet Peas flower for a long season. If sweet peas are not regularly dead headed, the blooms will get fewer and fewer, dead heading keeps the plant going and I have picked sweet peas right through to November.
When planting out sweet peas pick a sunny spot, and they like moisture retentive soil which needs to be enriched with compost or other organic matter. If you encounter any problems growing sweet peas the most common problem is powdery mildew, a fungus which leaves white powder on the leaves. This fungus is much more likely to attack the plant if it is dry so it is important to water sweet peas especially in any dry periods. Video How to plant and grow sweet peas
Growing Sweet Peas
Sweet Peas are easy to germinate and buying seed gives a wider choice of fragrance and colour, but it is more time consuming. Many of the garden centres sell Sweet Peas seeds in mixed colours which is good, but it is also nice to have some single colours to contrast and complement other summer flowering plants. This type of sweet pea is an annual which means it will only flower for one season. There is a perennial sweet pea called Lathyrus latifolius which blooms every year and the flowers look very similar to the annual variety, but many of the perennial varieties are not scented. Sweet Peas are seeded in either Feb/March for planting out later in the year, or in the Autumn for the next year.
Growing Sweet Peas from Seed
Sweet Peas from seed is easy as they are quick and easy to germinate only needing heat to germinate and need to be placed on warm windowsill or heated propagator, about 15C/ 59F. When growing Sweet Peas from seed the choice of container is important; Sweet Peas have long roots which means it's important to plant them into a deep container not a regular pot. You can use either root trainers sold by all garden centres, or cheaper and just as easy, toilet roll holders, both are shown in the image left. If you are sowing Autumn sweet peas to overwinter they are best in root trainers and there is a risk the cardboard tubes will get damp, disintegrate and /or encourage mould over the winter. Equally, the cardboard tubes are just fine for Spring Sown sweet peas.
Put two/three seeds into the container placing the seed near the top to give plenty of room for the roots to grow down. Sprinkle with a light covering of compost, spray with water so the compost is moist not too wet and place in a warm place. It's essential for germination to cover with a lid or clear polythene. Germination should occur within a few days and as soon as the sweet pea seedling is a few centimetres above the soil, if in a heated propagator remove so as to prevent the seedling getting too warm which will make it sappy and not very sturdy. Only use the heat to speed up germination. It is very important not to allow the sweet peas too much heat after they have germinated, or to keep the propagator lid on for too long. If the seedlings over heat they tend to go leggy and have less study stems.
Sweet Peas can also be successfully germinated in the Autumn in a warm conservatory and the moved into an unheated greenhouse for the winter. Provided the Sweet Peas are protected from frost under glass they will do well over the winter and produce sturdy plants for the Spring. Autumn sown Sweet peas tend to flower earlier and by sowing both in Autumn and Spring the flowering season is extended.
Whether you sow in Autumn or Spring, young Sweet Peas at the seedling stage, pinch out the growing tips to make the seedling bush and produce more growing tips which will in the summer make more flowers. Looking at the images below, left shows the young sweet peas removing the top growth and right image every seedling has the top growing point removed. The centre below was taken a about 10-14 days after the top had been pinched out and you can see instead of just the single stem there is now a side shoot. Pinching out the growth point makes the sweet pea throw out more shoots to have multiple stems not just one. Autumn sown sweet peas, and peas sown early in the season will often need pinching out several times to nip out the top growth before planting out.
Growing Sweet Pea Tips
Plant out in spring when the risk of frost has passed. Sweet peas are half hardy so can go out earlier than bedding plants but avoid spells of cold wet weather
Sweet peas like rich soil with plenty of compost
Plant in a sunny spot
Provide support trellis, obelisk or a frame to climb up
Take out the tendrils do not let these grow uncheck - Why? See how to get straight stems on Sweet Peas
pick pick and keep picking sweet peas don't let the seed head form image below identifies Sweet Pea seed heads