Known for its delightful fragrance, Sweet pea (Lathyrus odorata) is a delicate vining beauty that will add color and charm to your landscape. While there are a handful of varieties that are perennial, the sweet pea is considered an annual with flowers that bloom in shades of red, pink, blue, purple, and white. Sweet pea will grow to be well over three feet tall with support. It can provide a pretty backdrop for lower growing plants and is stunning enough to be a stand-alone garden feature.
Where sweet pea flowers originated is uncertain. Botanists have been enchanted with the sweet pea as far back as the late 1600’s. In the 1800’s, a botanist from England named Eckford began hybridizing and selecting these beloved garden treasures to develop beautifully formed large varieties. As the sweet pea evolved and became hardier in cool climates, it became more accessible. More and more gardeners began to enjoy and embrace the fragrant beauties. Sweet pea varieties eventually made their way to the U.S. where growers have developed varieties more tolerant to the region’s hot and humid summers.
Planting sweet pea
There are a few rules to follow when planting sweet pea. Sweet pea loves the sun, so provide a full sun to partial shade location. However, keep in mind that while it thrives in the sun, it will not bloom if feeling overheated. For hotter regions, afternoon shade will provide some heat relief. Sweet pea is a good garden choice for cool, dry garden areas.
The sweet pea requires moist soil with excellent drainage. Give your sweet pea plants elbow room to promote good air circulation. Mulch around the base of the plant to keep the roots cool.
Your sweet pea plants will need a support. Provide the support when you plant the seeds or transplants. These lively growers will need the support soon after germination. Guide the first tendrils to the support, and the sweet pea will trail upwards on its own after that.
Plant sweet pea from seed. Where winters are cold, plant seeds indoors in individual 3 to 4 inch containers in early spring. Transplant carefully without disturbing the roots. Sweet pea seedlings are hardier than most annual seedlings and will handle a touch of frost after you have transplanted outdoors.
Where winters are more mild and summers are hot, plant directly in the ground after Labor Day. This will give the seeds time to put roots down and to become vigorous growers in the spring. Plant directly in late spring in locations with milder winters and cooler summers where you can enjoy late summer blooms.
Pests and problems
Young sweet peas are susceptible to birds, slugs and snails until they are four or five inches tall, so protection from these pests will require a diligent and keen eye. The sweet pea is also prone to mildew, so give it room for good air circulation to curb this problem. Aphids and thrips are potential pests for the blossoming sweet pea. The blooms do not respond well to insecticidal soap, so a strong spray of water will usually thwart the aphids. Blue sticky traps hung among the plants will draw the thrips away from the plants.
Sweet peas grow and behave much like their relatives, edible peas. However, sweet peas are not to be eaten. The seeds that are produced by the plant after blooming are poisonous if ingested in large quantities.
Sweet pea varieties worth trying
‘Cupid Color Palette’ is a dwarf variety of sweet pea that will cascade 8 to 10 inches. This variety will add a graceful touch to a window box or small garden area with pink, white, and lavender (mixed/bi-colored) blooms.
‘Saltwater Taffy Swirls’ is a yummy-looking variety that will vine 6 to 8 feet. Its blooms are swirled in all colors and creams.
‘Velvet Elegance’ is a regal beauty that grows 6 to 8 feet tall with maroon, violet-blue, and crimson-red flowers and is unique because it is not particularly fragrant.
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