Simple guidelines for growing sweet pea vines

Popular as fragrant cut flowers as well as garden vines, sweet peas bear elegant blossoms in white, yellow, pink, red, purple, blue, and bicolours. Follow these guidelines to get this gorgeous vine growing for you.

• Old-fashioned types, such as 'Old Spice' hybrids, have the headiest perfume but usually fewer and smaller blossoms
• Modern types boast long wands of fluttery flowers in luminous shades but aren't as aromatic
• Most grow 1.2 to 1.8 metres (four to six feet) tall and usually have stiff, upright stems if given the support of a string or net trellis
• There are also bush varieties sufficiently compact to use at the garden's edge or in containers

• Sweet peas require cool weather, and young plants are surprisingly hardy
• While regular sweet peas grow and flower poorly in hot weather, the perennial pea (Lathyrus latifolius) can take the heat. This vigorous vine, which grows to three metres (10 feet), produces pink or white blossoms that resemble sweet peas but do not have their sweet scent. Perennial sweet peas are dependably hardy to Zone 4 and flower through the hottest summers
• Spring vetchling L. vernu (Zone 4) is a non-climbing, mound-shaped plant with mauve to pink flowers that bloom in early spring. It needs a semi-shaded location where it is protected from summer's fierce heat

• Soak seeds overnight in water and plant them five centimetres (two inches) deep in cool garden soil that has been deeply dug and amended with organic matter, such as compost
• Time the planting to take advantage of cool weather
• Plant as soon as the soil can be worked in cool regions

Cold-climate gardeners can jump-start the season by sowing seeds indoors in late winter, using individual peat pots.

• Keep the soil barely moist and grow the seedlings on a sunny, cool windowsill
• Transplant them into the garden two weeks before your last frost date, after hardening off
• Handle seedlings gently, planting peat pot and all, and disturb the roots as little as possible
• Be sure to completely bury the peat pots or they will evaporate water from below soil level

• Mulch the soil around the roots with an eight-centimetre-thick (three-inch-thick) layer of chopped dried leaves, straw or shredded bark to keep the roots cool and moist
• Install a trellis early on and help the young plants find the support if their own search falters
• Pick off spent flowers to encourage continued flowering
• If you see the small, pear-shaped, sap-sucking insects known as aphids clustered on the leaf undersides of new growth, knock them off the plant with a forceful spray of water. Or apply insecticidal soap according to the package directions
• Four-footed pests, including deer, rabbits and woodchucks (a.k.a. groundhogs), nibble sweet peas. Fencing them is the best defense, but applications of a commercial repellent used as directed on the label is somewhat effective

• Attributes: Delicate foliage; dainty, fragrant flowers; for trellises, cut flowers
• Season of interest: Spring to summer
• Type of vine: Tender annual; climbs by clinging with tendrils
• Favourites: 'Winter Elegance' for hot climates; 'Old Spice' hybrids for fragrance
• Good neighbours: Lobelia, pansies or sweet alyssum
• Where it grows best: Areas with mild winters, cool springs or consistently cool summer nights
• Potential problems: Heat stress, aphids
• Renewing plants: Reseed each year
• Critter resistance: Poor; shoots vulnerable to deer, rabbits and woodchucks (a.k.a. groundhogs)
• Source: Seeds
• Dimensions: Annual: 1.2-1.8 m (4-6 ft); perennial: 3 m (10 ft)

With a little planning and minimal effort you'll soon enjoy the fragrant blossoms and vibrant colours of this low-maintenance vine in your own garden.