Growing Lathyrus Odoratus (Sweet Peas) in Zone 6b/7
I’m back with another growing tutorial! Want to see the post with photos and videos in it’s entirety? Click here! Hooray!
Sweet peas (not the edible kind) are gorgeous and smell absolutely divine! Unfortunately, however, they can be somewhat difficult to grow depending upon where you live. In fact, before I started growing flowers for myself, I had never even seen them “in real life”. Sweet peas are a wonderful addition to the flower garden. Hopefully, this post helps others start bringing the joy of vintage plants back into their homes!
When to plant sweet pea seeds depends greatly upon where you live. If you live further North, where temperatures in the spring remain cooler, it’s likely you’d be fine planting sweet peas in the spring time. However, some gardens (like mine) experience very little spring weather before temperatures soar into the 80s and 90s. My garden is in Kentucky, zone 6b/7. It’s not uncommon in my area to feel as if we “skip” spring and have hot, humid weather early in the season. These are NOT ideal growing conditions for these delicate blooms. Ideally, we want cool and moist soil as the plants begin to grow. This means that I have to start thinking about spring blooms way ahead of time!
Regardless of whether you’re planting in the spring or the fall, the first step to planting sweet peas is to soak the seeds 6-8 hours in water. Some folks I know insist that you should soak the seeds overnight, but the shorter amount of time seems to work just the same, without the worry of over-soaking (and the seeds later rotting in the ground).
Sweet peas are very heavy feeders, so it’s best to be generous when amending the soil. Plants grown in soil without enough nourishment will be small and disappointing. Trust me, I’ve learned from experience! As I prepare the beds for planting, I add both compost and pelleted seabird guano. The sweet peas seem to absolutely love it!
After we’ve soaked our seeds and amended our soil, it’s time to figure out how we actually want to plant our sweet peas. Whether planting in the fall or the spring, direct sowing is an easy option. Seeds germinate well in cooler temperatures (as soon as the soil can be worked in the spring). However, it’s also important to note that if the soil is too wet or too cold – the seeds will rot. Ugh! Sowing seed indoors, or in containers is another great option. Although, it’s important to keep in mind that sweet peas can have extremely long tap roots. Hence, the importance of working the soil deeply! Sweet pea seedlings will not be happy in traditional seed starting trays. While many people use something called “root trainers”, I’ve found that I can cheaply accomplish the same task by cutting 2 litre soda bottles in half and filling them with soil. Cheap and easy!
Sweet pea plants are surprisingly cold tolerant. Even in my zone where temperatures can dip down to 0F on occasion, I’ve had great success with direct sowing in the fall and overwintering the seedlings until spring. If you have a greenhouse or hoophouse, that’s even better! Without any winter protection in my zone, the survival rate of sweet pea seedlings through the winter is about 50%. When covered with a layer of 6mil plastic sheeting from the hardware store (like a low tunnel), that number goes up to about 98%. For me; the whole process is based on trial, error, and pushing the limits of my growing zone.
If the idea of taking a “risk” by planting in the fall doesn’t appeal to you, don’t worry! There’s yet another option! Winter sowing! Now, let me be clear – I mean the winter sowing method. If you’ve never heard of it before, I’ve included my video for it above. I discovered this method a few years ago, and when I say that it was a total game-changer for my garden – I mean it! The winter sowing method is great for anyone that has trouble germinating flower seeds, doesn’t have money for an indoor setup, doesn’t have the space to start seeds indoors, and still wants gorgeous flowers! In my zone, sweet pea seeds planted in containers at the beginning of February germinate and begin growing. By the time the soil is workable, the plants are the perfect size for transplanting. Everyone’s garden is different, so of course, getting the hang of winter sowing may take some trial and error, as well! If you’re going to winter sow sweet peas, do NOT soak the seeds! Nature will take care of that for you!
Once the seedlings grow to be several inches tall, “pinching” back the plants will help them to produce more blooms later. Since we’re not growing these for exhibition, we want there to be as many flowers as possible. Simply snip off the growing tip when plants reach about 6″-8″ in height. Make sure to leave several sets of leaves on the stem. When planting in the fall, I wait until the next spring to pinch the flowers, regardless of their height.
That’s it! You’ve planted, amended, fertilized and pinched! Now, it’s time to sit back and enjoy the insanely sweet and beautiful fragrance in your garden! Unfortunately, sweet peas are very short-lived in my garden. Once the weather heats up, the plants begin to yellow and fade away – this usually happens around the first week of July here. Bummer! Aphids are another concern for sweet peas, but are easily controlled with a strong burst of water from the hose.
Not only are sweet peas fabulous in the garden, they also make great cut flowers! Check out this mini-bouquet that I was able to make with some of my fall sown hardy annual flowers! If you’d like to see more “how to grow” videos, let me know in the comments!