My family heirloom vase waits all year for sweet pea posies.
Anyone who has spent a few growing seasons with me will tell you, sweet peas are my totem plant, a generational touchstone and possibly the most satisfying cut flower in my summer garden. It used to be that every year, right around Valentine’s Day, I would go through the ritual of soaking, sprouting, and starting seeds. Dreaming of the fragrant blossoms to come, no task was too fussy for my ritual offerings to the church of Lathyrus odoratus.
Then, a few years ago I came across Ardelia Farm where proprietors Thomas McCurdy and Bailey Hale grow more than 150 varieties of sweet pea on 50 acres in northern Vermont. After reading their online growing guide, I followed their advice. Not only were my starts sturdy and robust, the seedlings flowered early, yielding and an even longer season of beloved cut flowers.
A bouquet of fragrant sweet peas — yes please.
Chill out
Today’s blousy sweet peas descend from a wildling discovered by a Sicilian monk in the late 17th century. Nearly 200 years later, the decidedly modest but powerfully fragrant flower made its way to England and sweet pea breeding exploded. Some of today’s varieties still bear the names of plantspeople, like Sutton, Eckford, and Spencer, who gave us the plant that we know and love today.
Which is a long way of saying that sweet peas thrive in England’s cool, damp climate, a familiar scenario to this Pacific Northwest gardener. The following approach to starting plants is common among English growers, with a hat tip to the Vermont farmers who kindly spelled it out for me.
Sweet peas prefer cool, even cold growing conditions. Starting seeds early in the year allows for the development of a sturdy root system. Beginning in early winter, start plants in a chilly basement, garage, or an exterior shed where temperatures hover around 50-55 F. That’s significantly cooler than most indoor temps.
I’m partial to warm melon blooms, this one is possibly Prince of Orange.
Get planting
Sow seed about ½- to 1-inch deep in a well-drained, coarse potting mix. Deep pots are preferable to shallow growing trays. Ardelia Farm recommends that you skip soaking, nicking, or otherwise pre-treating seed to avoid exposing plants to fungal disease.
After about 10 days, longer if conditions are cooler, you’ll begin to see tiny sprouts emerge. At that point, move the seedlings (still in their pots) to an even cooler location, like an unheated greenhouse, a covered porch, or a protected location out in the garden. Provide full natural light, the more the better. Pro tip: Protect plants from mice, birds, slugs, and snails who can, and will, devour seedings in a heartbeat.
Sweet peas thrive when temps are around 45 F. during the day with overnight lows around 35 F. “No worries,” the Vermont sweet pea guys say. “A hard frost, right down to 20 F. is fine.” I guess they should know, Vermont winters run frigid. When grown cold, top growth on your seedlings will be short and stocky but the plants’ roots are actively growing.
‘April in Paris’ is an especially fragrant sweet pea with nice cutting stems.
Out into the Garden
The experts at Ardelia advise planting sweet peas into the garden when you see daffodil growth emerging. Sweet peas are heavy feeders so amend your planting bed with plenty of manure, compost, and organic material. As the weather warms, your well-rooted plants will leap into active growth. To encourage robust branching, remove the top set of leaves, leaving 2 or 3 sets on the young plant.
Unless you’re growing a dwarf window box variety, you’ll need to put some sort of support in place to accommodate the clambering vines. Twiggy brush, wire fencing, or a teepee strung with string all provide purchase for the vine’s fine curling tendrils to cling to. It’s not uncommon for vines to reach 6 or more feet tall, so plan accordingly.
Once flowering begins, keep flowers picked to encourage more blooms. Eventually, summer heat shuts down sweet pea season – unless is doesn’t, as sometimes heat deprived Northwest gardeners can attest.
Lorene, thanks for this great advice. For several years we used to sell a wonderful collection of sweet pea varieties from Thompson and Morgan here at the nursery. My wife always made sure we had a few growing in our garden as well, she being 50% English due to her mother being a “war bride”. We always looked forward to that first vase of heavenly scented beauties sitting center stage on the breakfast table. Last year was a really odd year for us as it seemed like it took forever for my seedlings (and a few transplants) to finally get growing. I was picking flowers in July and even into August which wasn’t nearly as satisfying as a having them much earlier in the season. Sadly, my wife passed this last November and my first thought was that I would take a year off from planting all the veggies and flowers that I always did and just focus on maintaining the rest of the garden. But, I don’t think I will be able to forgo the sweet peas. She would be disappointed if there wasn’t a arrangement of these sumptuous little guys front and center like always.
Dear Steve, I am so very sorry for the loss of your wife. I’d encourage you to plant sweet peas for her and for you. These little, sometimes fussy annual vines are powerful medicine for the soul.
I have never grown sweet peas and I am green with envy. Margaret Roach, on her Way to Garden podcast, had Matt Mattus on a few weeks ago. He’s in Massachusetts and also shares a passion for sweet peas. My trouble is: I live in hot and humid Kentucky that I know is not the most favorable climate. I may give them a go this year, anyway. What the hell…Thanks for your story, Lorene.
Hi Allen, I read Margaret’s interview with Matt and I’m envious of his mad bamboo tipi skills! Years ago I had a group of garden writers in my garden including a friend from Oklahoma who had never seen sweet peas in a garden. It was so sweet to see her glee – we always want more. Me? I’d love to have fireflies~
I live in So Cal with very little yard. I have planted sweet peas in a very large clay pot, they are about 2 inches tall now. I have a tepee for them to grow on. Hoping to have their wonderful smell later on.
Hi Dianne – This tracks with my memories of my Nana in So Cal. Winter into early spring was sweet pea season.
Thanks, Lorne, for the timely tips. I’ll head down to the cool greenhouse & get planting.
My tip comes from years of slug depredation on my beloved sweet peas. I finally licked them with copper tape around the legs of my plant bench, & copper mesh, cut into 2” x 2” squares, with a slit cut to the middle to accommodate the stem of the seedling. Nothing else was successful. I garden in Oregon’s Willamette Valley.
Oh what we won’t do to protect our seedlings. Good luck!
When I was in England this summer I had sweet peas by my bedside-absolutely dreamy! I’ve succeeded in growing them in Texas, but our heat melted them all too quickly. The Margaret Roach interview and your post have made me wonder if I should make a second try, but get them going earlier.
Starting now — or even earlier — might be the ticket to sweet pea success!
Thanks so much for sharing this informative post, Loren! I work with Bailey and Thomas at Farmer Bailey, and we love to see our fellow sweet pea lovers succeeding with this magical flower. Sharing knowledge is everything. If I can ever be of assistance to you, do reach out!
what a treat it must be to work among the blooms!