American gardeners don’t grow sweet peas (Lathyrus odoratus) as often as their English counterparts, and that’s a shame. While it may take a little more care and choosing heat tolerant varieties in the Midwest, having some sweet peas in the garden is well worth your time. These little beauties will fill the air with their delightful sweet scent and there is a pleasing range of colors to choose from. If you like heritage vining flowers there are sweet pea varieties to suit you. If you don’t care for annual vines there are now sweet pea varieties that are great for hanging baskets, spilling out of containers or forming groundcovers. As a bonus, bees and other pollinators love sweet pea flowers.
In earlier times sweet peas were grown for cut flowers and they still make sweet smelling long lasting bouquets. English gardeners grew them, and still do, for flower competitions. Dozens and dozens of varieties were developed; thankfully many of those have been preserved if you take time to search them out. Some of the earliest genetic and plant breeding experiments were carried out on sweet pea plants. Several species of wild sweet peas were used to make garden sweet peas.
Most sweet peas are annuals, but they will often self-sow when grown in the garden. There are perennial varieties but these, while pretty, are smaller flowered and not fragrant. In general sweet peas form long vines which cling by curling tendrils around the object they are climbing. Shorter vined plants have been developed for baskets and containers and bushier plants for ground covers. The leaves of sweet peas vary from thick fleshy rounded leaves to narrow grass like foliage.
Sweet Pea varieties and where to get them
Most seeds and plants are sold as mixed colors although you can find named color varieties. Plants may be hard to come by at your local nursery although at least one on line garden catalog-
http://www.selectseeds.com - carries potted plants. Other catalogs that carry sweet pea seeds are
Some of the larger flowered, newer sweet peas are less fragrant than older varieties. If fragrance is important look for varieties labeled very fragrant. Here are some cultivars to look for.
Larger vine varieties
Fragrantissima many vibrant colors and very fragrant, large flowers
Old Spice, mixture of colors, fragrant, heat resistant and strong vines.
Spencer mix- variety of colors, large ruffled flowers with moderate fragrance
Chocolate Streamer- White flower base with chocolate speckling, rare
Beaujolais red wine color flowers, fragrant
Blanche Ferry, rose pink flowers an old American variety. named for daughter of DM Ferry seed comp.
Prince Edward of York- cerise and carmine flowers fragrant- 8 feet vines,
Prince of Orange Spencer – large clear orange clusters of flowers, mild scent
Queen Alexander – Scarlet flowers- fragrant
Lady Grisel Hamilton- lavender and mauve flowers, very fragrant.
Mollie Rilestone- cream flowers edged with pink with a light yellow flush
Rose pink Mammoth- very large pink flowers with white center but only mildly fragrant
Blue Celeste- large ruffled blue flowers with a strong fragrance
Short or compact vines
Sugar and Spice- smaller, good for baskets compact growth- color variety, fragrant
Cupid Black – dark purple, 8 inches high for baskets or ground cover
King Tut- blue flowers smaller – 3 feet vine, good for warmer areas
Color Palette- mixture of colors, compact for baskets
Windowbox Cupid – color variety, short vines
Perennial, wildflower types – not fragrant
Lathyrus sativus azureus- tiny blue flowers on short vines, sometimes sold as variety ‘Electric Blue’
Lathyrus latifolius- usually sold as a mixture of pink, white and lavender flowers, smaller than cultivated flowers and long vines.
Sweet pea culture
Sweet peas like a sunny location in rich moist, but well drained soil. The seeds or even plants can be planted a few weeks before your last expected frost as light frost won’t harm them. Plant them early because they love cool weather. Mice and birds can be a problem when seeds are planted as both love the seeds. You can place netting over spots where seeds are planted. If mice keep getting your seed sprout the seeds inside and transplant seedlings outside. In fact northern gardeners may want to start their sweet peas inside in April so that they get flowers before late summer.
Sweet pea seeds can be a bit stubborn in germinating as they have a tough seed coat. Many gardeners nick each seed coat with toenail clippers or a similar item. You can soak them until slightly swollen before planting but don’t let them soak more than 12 hours or you will probably “drown” them. You can also place the seeds between layers of damp paper towels and place the towels in a plastic bag in a warm place. When the seeds begin sprouting plant them outside. If the tiny roots are anchored in the toweling tear off pieces of the paper towel with the plant attached rather than yanking them off the towel and plant paper and all.
No matter whether you plant seeds or seedlings keep them moist during their early growing periods. And as warm weather comes make sure to water your sweet peas regularly as they do not like drought conditions. Sweet peas are also heavy feeders so mix some slow release flower fertilizer into the soil before planting or water occasionally with water soluble fertilizer. This is especially important to keep container and basket plants blooming.
Vining types of sweet peas will need something to climb. Trellis or teepees of bamboo stakes can be used or plant them where they can climb fences. They don’t climb building walls well as they need to twine around something.
Your plants will begin blooming anywhere from 60 – 90 days after they were planted, depending on variety. If summer is very hot blooming may be delayed until cooler weather. Pick the flowers or keep the dead blooms picked off before they develop seeds to prolong blooming time. Once they begin blooming if they are faithfully dead headed they may bloom until a hard frost. At the end of the season you may want to let a few seed pods develop and ripen to store the seeds for next year. Since sweet pea varieties cross pollinate easily you may get different looking flowers next year.
The most common problems with sweet peas are aphids and powdery mildew. Aphids can be controlled by washing them off the plants. Powdery mildew usually doesn’t strike until late in the season, right before the plants will die anyway. To help prevent it make sure the plants aren’t crowded and have good air circulation. You can also use garden fungicides if you wish.
Sweet Pea seeds are not edible and some are poisonous so don’t let children or pets eat the seeds. Don’t cook the pods or seeds or use them in salads. Sweet pea flowers also should not be eaten.
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Great native shrubs for the landscape
Growing Brugmansia and datura