Top Ten Performers: #8 Sweet Peas

Sweet peas come in a wide range of colors

I wish I could grow luscious sweet peas (Lathyrus odoratus) with 10″ or more stems and huge flowers like they do in the Pacific Northwest or in high tunnels in cooler climates. I can’t (or at least I haven’t yet!) but they are still more than worth growing here in north central Indiana. They love a long, cool growing season and hate heat, so Indiana is not their favorite place to grow but with an early start and choosing the right varieties I’ve found some success.

Sweet peas still looking fairly good at the end of July

Sweet peas grow in in a wide range of colors and often bi-colors. From pure white, through many shades of pink and rose, almost orange, to bright red and deep burgundy, and shades of blue to purple there is a broad spectrum from which to choose. Some have contrasting edges, or a combination of two different colors (white & bright red, blue and purple are two examples) of petals in a single flower. Some are ruffled, some have streaks of other colors in the petals. Most of the heirloom varieties have a wondrous sweet scent that gave them their name, but some of the newer introductions that boast larger flowers have often lost their aroma. I prefer the ones with the heavenly scent!

A bouquet with dahlia, larkspur, snaps, feverfew, parsley blooms, talinum and graceful sweet peas.

There are SO many choices, but some strains tolerate heat better than others, some have more scent, some have longer stems, etc. Geo lists 16 climbing varieties. The names often indicate heavy scent: “Incense Mix,” “High Scent,” or “Old Spice Series.” I grew “Mammoth Choice Series” because it was reputed to do well in heat and had long stems…very pretty but little fragrance. “Melody Mix” has large bi-color flowers and long stems and is very sweet scented. “Queen of the Night” has lots of navy blue, dark burgundy and bi-colors. The Spencer Series is highly touted but they are too late-flowering for my area because just as they are ready to open our “spring” suddenly becomes summer and they just can’t take our heat. There are also another 6 varieties that are short (8-30″) for containers or hanging baskets (Cupid, SuperSnoop, Bijou, Little Sweetheart, Knee-Hi, Villa Roma)

Sweet peas climbing a trellis in the potager add a lovely fragrance to the garden as well as to bouquets.

Be aware that there is an old heirloom perennial variety (Lathyrus latifolius) that my mother grows in partial shade with rosy-pink flowers (no scent) that is a rampant self-seeder. I had it once at the herb farm and it was a pain to keep out of the paths and from taking over the entire garden!

Perennial Sweet Pea…Pretty, but no scent and a prolific self-seeder

In prior years, I was fairly lazy when it came to sweet peas, trying several different varieties in various locations but not giving them much thought. In 2022, I planted “Mammoth Choice” sweet peas on February 5th and they germinated in only 5 days. They were planted outdoors under a row tunnel on March 14, and the first flowers were picked May 24. Obviously they did well, or they wouldn’t have made it into the Top Performers roster at all! But, I know I can do better.

Sweet pea tubes ready to be planted out!

Starting them earlier this year may produce earlier flowers, at least I’m giving it a try. Sweet peas can tolerate temperatures down to 23 degrees F. I soak the seeds overnight and plant them in toilet paper tubes (2 seeds per tube) with a potting soil that contains perlite for drainage. Cover with 1/2″ soil and grow at 55-65 degrees. When they get two sets of true leaves, snip or pinch them back to the first set of true leaves. This will encourage basal branching. Keep an eye on their roots and pot them up a size if they appear to be getting root bound. They do not like root disturbance, which is why I grow them in tubes. Grow them on for about 6 weeks, then plant them out 8″ apart into good soil. Last year I just planted them out into my raised bed soil. This year I’m adding compost, bone meal, and a sprinkle of lime in each planting hole because I’ve learned that they are heavy feeders. You’ll need to provide a sturdy trellis or grow them along a fence. I’ve also learned that mulching well to keep the roots cool will lengthen the flowering period, so I’m doing that as well. Keep them watered consistently, using a liquid fertilizer in the water at least weekly because they are really heavy feeders.

A bucket of sweet peas ready to arrange

When harvesting sweet peas, early morning is best. Harvest when 1/4 to 1/2 the flowers on a stem are fully open and place stem ends in several inches of COOL water with flower food dissolved in it immediately. If the flower stems are long enough, just cut those. However, mine rarely are, so I pick “branches” the length that I need. Sweet Pea foliage is very attractive, adding a touch of elegance an whimsy with their pretty leaves and dainty curled tendrils. Sweet peas are another plant that the more they are picked, the more they produce.

Sweet pea seed pods drying. It is easy to save seed from various varieties.

If there are flowers left unpicked, the bees will quickly pollinate them and the plant will form seeds. Once that starts to happen, the plants quit flowering because they have fulfilled the need to propagate, so as I harvest I also snip off any faded blooms. Last year I had flowers from May 24 to July 21. I’m hoping to increase that time this year on both ends!

Bouquet featuring sweet peas, bells of Ireland, annual phlox, feverfew, larkspur, snapdragons, asters, dianthus, parsley blooms

This year I’ve already seeded some “Mammoth Choice” because they performed pretty well despite our heat. However, in an attempt to get more scent, I’m also planting “Old Spice” which has 25 highly scented strains and “exceptional heat tolerance” and “Heirloom Mix” which has lavender and salmon shades in addition to the “usual” colors. Because I need lots more blue I’ve also added “Royal Family Mid-Blue” with reputedly large flowers and long stems, but apparently little scent. The plan is to use some of the best fragrant ones along with some of the larger-flowered but less-scented blooms in each bouquet.

That’s the report on the #8 Top Performer. If all goes to plan and the improvements are made to their care, maybe next year they will be much higher on the list! Tension and anticipation are mounting…did your favorite contender make the cut? Only two more places to go….what, oh what will they be?

Advertisement