This is my first year trying sweet peas, though I’ve grown snap peas many times with great success (like fantasizing about sneaking snap peas onto neighbor’s doorstops to get rid of them successful :D).
But I can’t get my sweet peas to flower. Does anyone have any suggestions? I googled this to a fare thee well and got a lot of contradictory information. Fertilize…no DON’T fertilize, water, don’t water…lots of sun, little sun… etc.
At any rate, what I have are gorgeous healthy vines climbing like crazy (they’re about 3 feet tall now), but not a single bloom yet. I live in the Seattle area, so it’s a cooler climate like a lot of the googled references suggested (one of the few consistent suggestions). Since I live in an apartment, it’s a balcony garden. I have a nice-sized balcony, about 12 feet long and 5 feet wide, and the sweet peas and snap peas are in pots along the balcony rail and I fastened a trellis to the rail for them to attach to and climb.
All of the plants, trees, and flowers on the balcony are doing really well and the snap peas, which I’ve staggered in planters next to the sweet peas, are already flowering and will probably start producing pods shortly, so what gives?
If I cut them back will it stress them enough to start producing flowers? Is it too early in my neck of the woods? (our weather has been about 7 degrees cooler than is normal for this area at this time of year).
So I’ve come to the Dopers for help. I know someone here will have good advice.
I don’t have any advice but I’d like to commiserate–I have never gotten them to flower for me either. Vines sure, flowers no.
Carry on.
That makes me feel a bit better. 
Try to really goose up the potassium and phosphorus without increasing the nitrate. A Homeowner’s Guide to Fertilizer says “Phosphorus is provided as 0-46-0 and potash as 0-0-60 or 0-0-50.” Good luck finding either anymore.
Wait, are you growing edible sweet peas, or the flowers?
I’ve got two different vines, sugar snap peas, which I’ve grown for years with great success, and the flowering sweet pea (my first time), which are fine and healthy, but so far no flowers.
The sugar snap vines however, have already flowered. Oh, and they’re not mixed in the pots, the pots are staggered so that it’s …sugar snap pot/sweet pea pot/sugar snap pot…and so on.
And thanks Jane I’ll try that. I finally found a great nursery in my area (who would have thought it would be so hard to find good nurseries in this area?), so I’ll go see if they can help me out with the right mix of fertilizer.
I have no advice but I often see them growing wild on hillsides here, flowering, with no help from humans at all.
How hot does it get in the afternoons for you now? I have sweet peas in my yard and they’re just now finishing and setting out pods. Then again, I’m in north Texas, and it’s been in the 90s for a little while now. So maybe, since it’s cooler where you are, they’re just not quite there yet?
Sweet peas + sugar snaps growing near each other will produce … interesting offspring.
I never had much luck with them either. My mother would just stick them in the ground (in Anchorage) on a southern exposure and the perfume from the flowers could asphyxiate a large mammal. I don’t know how she did it.
On a related note, I like to plant all kinds of violas and pansies near each other to see what comes of it.
I don’t have much advice for the sweet peas, either - they grow and flower just fine here, with no help other than something to climb up. I think of them as one of the easy flowers to grow. 