How to Grow Sweet Peas
Updated: Mar 9, 2022
If I had to grow one flower from seed it might be sweet peas. Fragrant and delicate, these beauties are not commonly available for purchase as cut flowers so the best way to get them is to grow them yourself.
Step-By-Step
Source your seeds, see this article for where to find quality seeds.
Soak your seeds over night to jump start germination..
Plant shallowly in pre-moistened soil and place on a seedling heat mat with a humidity dome if you have one or cover with plastic saran wrap. Here you can learn more about seed starting supplies I LOVE.
When the seedlings poke through the soil (anywhere from 2 days to 2 weeks after planting), move remove cover and heat mat and place under grow lights.
Once your seedling is at least 4" long and has at least two sets of leaves, pinch the remaining growth.
Plant out near a trellis or other support system once all danger of frost has passed (late May in Colorado). I like to plant mine in antique birdcages, the vines grow up and around the cages and then explode into fragrant blooms.
Keep your sweet peas moist and cool, they do not like high heat and do not tolerate drying out.
Sweet Peas at Petals
Think Local
We get our sweet pea seeds from other local growers. The very best seeds came to me via my dear friend Regina who handed me a brown envelope on cold January morning with the words,"fuchsia, hardy" scrawled on the front. Some gardener, who's name is lost to time, had given them to her. These seeds are the best sweet pea I've ever grown. I often have a hard time getting sweet peas purchased from seed companies to germinate, but not these bad boys. I collect as much seed from them at the end of the growing season as I can.
Not everyone is blessed with a random packet of magic sweet pea seeds but that doesn't mean that some gems are hiding amongst the gardeners in your community. Consider starting a seed swap and invite all your garden friends to share their seeds (no one really needs 100 basil seedlings, believe me). Seed swaps are a great way in increase the variety off what you grow without breaking the bank. Plug for Petals : We host private events, one of our favorites is a client who books our design studio for her seed starting party every March!
We pre-soak and plant our sweet pea seeds around March 10th, they are pinched back by April 1st.
Harden Them Off...gently.
Its hard to remember that seedlings need an extra gentle introduction to the Colorado elements as our elements are, well, rather harsh and a bit erratic. We move our sweet peas from their seedling trays once they reach about 6" tall and pot them up in a bunch of antique bird cages I collected from thrift stores one year (it was a phase, don't judge). The bird cages hang out in our design studio until about May 1st when we move them into the unheated greenhouse (thinking of putting in a greenhouse? You totally should. Here's a link to how to get started). They live there until the end of May when we hang them on our porches.
Keep Cool and Wet
We keep our sweet peas moist and in a bit of shade hanging under the porch eaves. Watering antique bird cages is difficult, but we like a challenge...if it involved plants. Our sweet peas produce until about July when they give up on Coorado Summer and we let them ramble and die back.
Plan for Next Year
We collect the seeds in September when we clean out the bird cages for storage until next year. Keep the seeds in a brown paper bag or someplace where there is enough air exchange that they won't mold (ziplocks won't do).
