Growing Sweet Peas For Lovely Cut Flowers
Sweet pea flowers might look delicate, but they are some seriously strong and vigorous plants! This will be my fourth year growing sweet pea flowers successfully and I finally got the two most difficult parts down: germinating and timing. So, if you have ever been hesitant to grow these stunning flowers, read below to get my tips for success!
Why do I grow sweet pea flowers?
Warning: sweet pea flowers are NOT edible. All parts of this plant are toxic to people and animals.
Sweet pea flowers should not be confused with the types of peas we grow for eating (aka snow peas, snap peas, shelling peas, etc.) but they still have a place in my garden because sweet peas make the most beautiful cut flowers that have a scent completely unmatched by any other flower. Additionlly, sweet pea vines are extremely prolific, the flowers come in almost any color, and the more you cut the flowers the more it produces!
When to Start Seeds
For those of us with mild winters (I’m zone 10b), the best time to start your sweet pea seeds is Fall. This allows time for the seeds to germinate and the plant to establish roots before getting an early bloom in Spring! If you live in a colder region, you can start your seeds in Fall and keep your seedlings protected through Winter, or you can choose to start your seeds in Late Winter/Early Spring for transplanting once the danger of frost has passed.
Sweet pea seeds can be directly sown into the soil, but I find that it is much easier to start them in pots and then transplant for a couple reasons: pest attacks & unpredictable weather.
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Sweet Pea Seed Starting Tips
Soak your seeds! Generally, I do not soak seeds. Most of the time the only benefit is quicker germination by 1-2 days and I don’t mind avoiding the extra work of pulling out bowls/jars and taking up counter space indoors. In the case of sweet peas, soaking makes a difference! I have found them a lot more finicky than most other seeds and soaking really encourages them to germinate in a timely manner. To soak your seeds, simply fill any small bowls or containers with water and drop the seeds in. Let them soak for at least 6-10 hours before planting.
Start your sweet pea seeds in a good seed starting mix (like my DIY one HERE) and follow package instructions for depth. You can also just push them into the soil 1/2″ deep as a general guideline. If you need a refresher on starting from seed and some of my best tips, check out my selection of articles dedicated to Seed Starting.
Location & Soil Requirements
Sweet pea flowers like rich, loamy soil that has been enriched by a good compost prior to planting. To prep my soil for planting, I follow the steps outlined in my article on Prepping Your Soil Organically.
They also perform best in full sun but can be grown in slight shade (not recommended). Throughout the growing season keep their soil moist, as they are water loving plants. Established and happy sweet pea plants are a lot more hardy than we think. I can personally attest that mine I have survived 90 degree days without even wilting as Spring was winding down and Summer arrived.
When selecting a location, keep in mind the size of the sweet pea plant at maturity. The majority of plants can grow 6-8 feet tall and will need support in the form of a trellis or arch that they can climb on. Personally, I think a wall of sweet peas looks so inviting in the garden.
What about fertilizing? You can really grow these without doing anything extra throughout the season—of course, that’s assuming you topped off your bed with some good compost. If you would like to feed your plants throughout the growing season, you can feed them with a seaweed or kelp fertilizer.
Related Article: How to Compost: Filling & Maintaining a Compost Bin
Can I grow sweet peas in a pot? Yes! See the photo below for a throwback to my very first time growing sweet peas. Try to use a pot that is at least 12 inches deep because sweet pea plants like to have deeper roots than some plants.
Pinching Your Seedlings
Yes, you read that right. You should pinch your sweet pea seedlings, and it’s not because they are just oh so cute. 😉
When your sweet pea seedlings have reached about 6 inches in size, pinch the central stem back to a leaf node (see photo below). Be sure that there are about 2-3 leaf nodes left on the plant. Doing this will encourage bushy growth for your sweet peas which will mean more flowers! See my photo below. NOTE: pinching is optional. If you don’t want to pinch your seedlings back, that’s okay too. You can still grow very nice plants!
The time to transplant out your peas depends on your climate. In my warm zone, we rarely get frost so I transplant my peas once they start to outgrow their pots in Spring or are large enough to fend off pests in the garden. In cooler climates, protect your sweet peas if you started them super early, and plant them out when frosts are starting to leave your garden in Spring. Sweet peas can handle SOME frost, so it is okay to get them in the ground a little early to start establishing. Don’t forget to harden off any seedlings you have grown indoors or in a greenhouse!
When transplanting I sprinkle some mycorrhizae fungi into the planting hole to help build strong root systems and prevent transplant shock. These beneficial microbes help the plants to have a better uptake of water and nutrients during their lifetime. This is optional, but you can view my favorite mycorrhizal product HERE and use code: randi15 for 15% off your purchase!
Protecting Your Sweet Peas from Birds
Each year I tend to have birds attack my sweet pea seedlings—this has even happened when I’ve left my seedling tray outdoors! I’ll typically utilize mesh baskets or random covers to (see some of my DIY Garden Hacks) to protect them, but I also had great success with fabric row covers for my vegetables and I wanted to share that with you. I created these DIY fabric row covers specifically to protect my directly sown and young seedlings last Winter, and you can see the difference it made!
Pick me! Pick me!
If you want to keep your sweet pea plants blooming, continuously pick flowers! If you don’t cut the flowers, they will turn into hairy seed pods which is called “going to seed.” This is a signal to the plant that the season is coming to an end. From experience, I have found that cutting the flowers for vase life is best done when each stem has not yet reached full bloom. This means that you should look along the stem and see which ones have some flowers at the end that are buds. If all flowers are fully open, still pick them (remember the note on “going to seed”) but essentially the vase life will be short. Pick them early!
Did you know? Some varieties of sweet peas naturally produce longer stems than others. So, if you are interested in growing flowers with longer stems for larger arrangements, read the description before buying and look for the phrases like “grows long stems” or “beautiful flowers on long stems.”
How to Save Sweet Pea Seeds
You can save your own sweet pea seeds to grow the next year. Simply leave flowers on the plant to expire and soon you’ll see what looks like a hairy pea pod emerging. The funny thing is, it’s almost like sweet pea seed pods are pressurized. If you leave them on the vine for too long, they get so dry that they almost spring open and cast their seeds everywhere! In my experience, I wait until the seed pods are brown and almost dry, cut them off and keep them in a brown paper bag in my garage. Once fully dried, you can harvest the round seeds from the pod and store in a cool, dry place. The brown paper bag will capture any loose seeds that have escaped their pods!
Before I go, I’d like to share a few of my favorite sweet pea varieties to grow so far: