Few garden scents are as memorable as sweet peas! In cultivation since the 17th century, many of us remember them from childhood in our grandmother’s gardens, or in bouquets. A must-have in any cutting garden, they can also be grown in containers, and in vegetable gardens to attract pollinators and scent the air while you spend time in your garden. Bonus: these climbers love our typically wet spring months and milder summers!
Light. Choose a sunny site and supply supports at least 6-7′ tall, for the vines to climb.
Soil. Thoroughly turn over and amend garden beds with aged manure or compost before transplanting. Sweet peas like neutral to alkaline soil, so for most of us that means adding lime (like what you use for lawns) to the soil also.
Test. If you have no idea what the pH of your soil is, consider getting it tested by a reputable lab. Free tests are available from the King Conservation District for Washington state residents.
Water. Sweet peas like consistent moisture! This produces the longest stems and biggest flowers, AND helps keep powdery mildew at bay.
Fertilizer. Sweet peas are heavy feeders! Molbak’s recommends Espoma Organic Flower-tone fertilizer, which is a granular slow-release form that can be added at planting time. Later in the summer, give plants an extra boost with Dr. Earth Flower Girl liquid fertilizer every two weeks.
Seeds. In the Pacific Northwest you can start seeds indoors or direct sow (planting directly into the garden) from mid-February to late March depending on the weather. Follow spacing and depth guidelines on the seed packet for direct sowing and when transferring outdoors.
Starting Indoors. Fill 6″ diameter pots with good potting soil. Soak seeds in water for 24 hours before planting. Push soaked seeds 1″ down into soil (5 seeds per pot) and cover. Water thoroughly then only give minimal water until after germination.
Transplant. Leave seeds to germinate on a sunny windowsill or in an unheated greenhouse. When seedlings are about 5” tall, transplant them to the garden (usually in early April).
REMEMBER: if you run out of time to start your seeds, Molbak’s carries an assortment of sweet pea starts for instant gratification! Call 425.483.5000 to confirm stock.
Cut, cut, cut. Preferably in the morning or evening when the air is cooler. Prevent seed pods from forming – the more you cut, the longer the blooming season will be.
When plants are about 6” tall, pinch out the center tip to encourage side branching – this produces more flowers.
Avoid powdery mildew – remember to water regularly and thoroughly, at the base of the plants. Sweet peas do not like to dry out.
Bait for slugs especially in spring.
Types of Sweet Peas
Old Fashioned. Climbing vines with highly fragrant flowers with long stems. Heat tolerant and long blooming; the classic sweet pea.
Spring Flowering. Stems have 4-5 flowers. Fragrance varies from slight to strong depending upon variety. (Cuthbertsons, Royals, Mammoth series).
Summer Flowering. Includes Galaxy, Spencer and Royal Family series, which are prolific bloomers if kept cut. Summer bloomers have the largest, most spectacular flowers and longest stems (up to 18″). Fragrance varies with variety. Intolerant of excessive heat.
Dwarf and Semi-dwarfs. Many varieties grow up to 24″ tall. Varieties include ‘Snoopy,’ and ‘Bijou’. These non-tendril types do not need a climbing support but benefit from a few twigs placed next to seedlings to add a scrambling framework. Dwarf varieties look great in hanging baskets.