Sweet peas (lathyrus odoratus) have always intrigued me. The scent, their beautiful frills... I used to try to grow them as high as possible, relishing in their vining and rebellious growth patterns. Now growing for cut flowers, it seems everyone has a different opinion on how to get the best scent, the longest stems and the most blooms. Through all this odoratus debate, one thing everyone can agree on is that you MUST get them planted early! Some of my friends (mates?) in the EU plant as early as December. I don't grow seeds indoors, I try to keep as close to good ol' Momma Nature as we can. So, this means that we have to wait a little longer to plant our seeds. I will plant one packet on the solstice just to push the [seed] envelope. The rest I'll be winter sowing end of January-ish. Sweet peas can be hardy down to zone 2. Yet, some varieties may need a helping hand to get through deep freezes. I find that setting their winter sown containers by the house gives enough shelter to keep them kicking through the chilly months.
Sweet Peas are large seeds so you'll have to plant them about 1" deep. I don't soak or scrape the seeds: mother nature does the soaking through winter sowing. It is worth mentioning that there is a plethora of sweet pea varieties; bushes, vines, short day length, scented, colorful, heirloom, hybrid colors, etc. To this I say start with the basics. "Mammoth" is an excellent variety and comes in a good mixture of colors, which is helpful for a beginner.
Sweet peas like cool weather. They grow best with shade on their roots and sun on their tendrils. Their roots travel down deep and are a great source of nitrogen as any bean or legume would be. Sweet peas appreciate a good soak, especially on hotter summer days. They prefer one long watering compared to multiple sprinklings. Although it's tempting, don't eat these frilly flowers or peas as all parts of them are poisonous. Give your sweet peas a good trellis or pole to climb up and they will flourish with gratitude. Most pro growers pinch off the top leaves (ahem- the apical meristem for my flower nerd friends) to promote branching and thicker stems. I find the best time to do this is once they are established in the garden and have more than 6" of growth. Because we grow so many, I will be pinching out about half and I'll let the others ramble. This saves time for me and lets me observe the plants natural growth patterns. I suggest that you experiment and find what works for you.
Keep an eye out for mice, as they devour sweet pea seedlings. A little bit of peppermint spray helps deter them for me. As for deer and other creatures, they tend to stay away due to the scent and poisonous nature. I have seen a few desperate deer sneak some nibbles, but they usually reject the bitter taste.
Sweet peas bring a sense of old fashioned joy into the home when used as a cut flower. Sweet pea bouquets are stunning in a bunch by themselves. They can pair nicely with godetia (also super frilly) or a simple agrostemma to enhance their exquisite ruffles. Tag us on Twitter, Facebook or Instagram so I can check out your beautiful blooms. Happy sowing :)