How to Grow: Sweet Peas
Of all the flowers I grow on the farm, Sweet Peas are the most deliciously fragrant.
I love to fill my house with bunches and bunches of them. After a long winter, it’s so refreshing to open the windows, bring the Sweet Peas inside and allow their intoxicating fragrance wash away all the staleness of winter.
Sweet Peas were always on my list of flowers to grow in my vegetable garden, but after 3 years of failed attempts, I decided it was finally time to get serious about learning how to grow them.
It turns out I was planting them MUCH too late in the season and they would just shrivel up and die on a hot day. When I finally learned the secret (plant them a LOT earlier than you’d expect!), I had my first Sweet Pea success.
They can be a bit fussy (and demanding) and sometimes I wonder why I even bother to grow them… but there is nothing else like them!
Let’s look at the Pros and Cons of growing Sweet Peas for cut flower use.
PROS
They come in a multitude of colors.
They are one of the most fragrant flowers you can grow.
They are elegant and romantic.
CONS
They can be tricky to start from seed.
They do not handle root disturbance well (more about this later…).
They do not like hot weather. They prefer moist, cool climates.
They do not last long in the vase (3-5 days).
They are extremely ethylene gas sensitive and expire quickly if exposed to it (this is the gas produced by ripening fruit, like apples and bananas).
They can be difficult to harvest, as the vines tangle into each other.
They need to be supported on a trellis or netting.
They are toxic and should not be ingested. Use caution around pets and small children.
CHOOSING SEEDS
Sweet peas have become increasingly popular in the last few years and there are many choices out there when it comes to seeds.
Honestly, I get overwhelmed by all the choices and tend to stick to the same types each year… but feel free to experiment!
Here are a few of my favorite Sweet Peas to grow for cut flower use:
“High Scent” (the most fragrant flower I grow on the farm!)
“Spencer Series” (I usually buy a mix of all the colors)
“Mammoth Choice Mix”
HOW TO SOW
Sweet Peas thrive in cool, moist environments and generally do best in the spring and early summer. When the heat of summer comes on, they tend to go to seed and die off.
If you live in a warmer climate, you may plant them in the fall or late winter. Colder climate folks can start them in early spring.
Here in Michigan, our last spring frost is about May 15. I try to get my Sweet Peas in the ground about 4-6 weeks before that.
Sweet Peas can go in the garden around the same time you would plant edible garden peas. I always plant my garden peas on Good Friday, which is usually in early April.
They require rich, well drained soil. If you struggle with wet soil in the spring, try growing them in raised beds. They are “heavy feeders”, meaning they are hungry for nutrients.
I dig a trench and fill the trench with well composted manure, then cover it back up with the soil and plant into that “compost filled” trench.
(*NOTE: Sweet Peas are NOT edible and in fact are considered a toxic plant, so use caution around small children and pets).
Transplants or Direct Sow?
Sweet Peas can be transplanted or direct sown.
For either method, soaking the seeds for up to 24 hours before sowing may help increase germination success.
Transplants can be started indoors about 4-5 weeks before planting them out. They are quite frost hardy and can be planted out when there is still a risk of frost (mine often get snowed on… and they are fine!).
Transplants will help you get a jump on the season, but be aware that Sweet Peas are fussy about being transplanted. Their root systems really, really, REALLY do not like to be disturbed.
Place 2 seeds per pot or container. Sweet Peas need a lot of room for their roots to develop, so plant them in the deepest containers you can find. 4” pots, like ones tomato plants often come in, will work. Or you can use peat pots that will naturally disintegrate in the garden.
The seeds can take up to 3 or 4 weeks (!!!) to germinate, so be VERY patient. Once they have sprouted up, then can be gradually hardened off and moved out to the garden.
Once in the garden, it’s not uncommon for them to “pout” for about 3-4 weeks after being transplanted (no matter how gentle you are with their roots!). They sit there, looking exactly the same way they did when you put them in… until one day they get over themselves and start growing like crazy. Be patient!
If you are direct sowing, sow them about 6 weeks before your last spring frost. Sow 2 seeds per hole. Make sure that the soil stays evenly moist the entire time you are waiting for the seeds to germinate.
I’ve had great success with direct sowing by watering thoroughly after sowing the seeds and covering the area with a thick layer of straw (about 6-9” deep). The straw keeps the soil evenly moist and deters birds and other pesky critters that want to eat the seeds. Pull back the mulch occasionally to check for germination.
Once the seeds have germinated, the straw makes a great mulch to help keep the soil moist and cool.
PLANT SPACING
Sweet Peas should be spaced about 6” apart. They are a climbing vine that can reach up to 10’ tall and need to have some kind of support to grow on.
GROWING ON
Sweet Peas are thirsty plants and need lots of water.
When plants are about 8” tall, pinch out the central stem. This will cause the plant to branch and produce more stems.
Sweet Peas enjoy a weekly fertilizer regimen in addition to the compost trench (demanding little buggers, aren’t they?!?). Fish emulsion fertilizer works great. Once they start growing vigorously, you can stop waiting on them hand and foot. ;)
STAGE OF HARVEST
Harvest stems when 1-3 blooms on the cluster are open. The remaining blooms will open up in the vase.
There are 2 ways you can harvest and it comes down to personal preference:
1. Harvest the bloom on the single stem. This is the “cleanest” method, but sometimes you’ll end up with short stems.
2. Harvest the bloom, stem and part of the vine with the leaves (like the photo below). This method looks more “wild” and allows you to choose the stem length of your choice.
POST HARVEST CARE
For longest vase life, keep them away from any ripening fruit. We always have bananas, apples, avocados, etc. ripening in our kitchen, so I cannot display Sweet Peas in the kitchen or they expire in about 24 hours. Instead, I place jars of blooms in our bedrooms and living room, where the sweet fragrance is especially welcoming.
QUESTIONS?
Ask them here and I’ll get back to you!
READY FOR MORE?
If you’re serious about growing the garden of your dreams this year, register for my online course, “Backyard Cutting Garden 101”. You’ll find everything you need to plan, grow, harvest and arrange your stunning blooms. I can’t WAIT to help you grow! Click on the button below for all the details.