Guide to growing Sweetpea - Lathyrus

Perennial Lathyrus grow similarly to annual Lathyrus, but are treated differently in the garden.

They reach heights of between 60cm and 3 M and flower from the late spring through summer with fragrant butterfly like leaves.

They can either be grown as trailing plants or attached to a trellis or fence.

Some of the common names for perennial Lathyrus include Sweetpea, Lord Anson's blue pea, perennial pea and everlasting pea.

How to grow Sweetpea

When growing sweetpea and other Lathyrus members outdoors from the off it is best to prolong the start of the growing season by protecting the soil with a layer of black plastic; this will help to keep the soil warm. Slits should be made in the plastic and the sweetpea seeds sown at a depth of 6mm at the start of spring. The plants will take about three to four weeks to germinate, as soon as they get to about 10cm in height, apply a mulch to the sweetpea plants. Sweet pea can grow in either a sunny or lightly shaded part of the garden. They prefer a soil of pH 6 to 7.5, as with annual Lathyrus the soil should be deeply composted (40cm)and have bone meal added to it.

If first preparing Sweetpea seedlings indoors, then start the growing process about 7 or 8 weeks before due to be transplanted out. First chip the seeds then imbibe them in warm water for a day. They will require to be inoculated with nitrogen fixing bacteria available from a garden centre. The seeds should then take two or three weeks to germinate at 12 to 18 degrees centigrade. Sweet pea should then be transplanted out following the last frost of spring at about 15 to 25cm apart.

Caring for Sweetpea

Once growing keep the Sweetpea plants regularly watered and remove dead flower heads to promote additional flowers.