Whether it is grown intentionally, or considered to be a common roadside weed, there is no denying that perennial pea, Lathyrus latifolius, knows how to brighten some of the wilder parts of the garden with brilliant purplish pink bloom. Some garden varieties bloom either pale pink or white, just like a few random feral plants do. Bloom resembles that of sweet pea, but without fragrance.
By their second year, the potentially six foot long vines might be a bit too rampant for more refined situations. They happen to work nicely to climb over wood piles and otherwise unsightly chain link fences though, even if only temporarily until they die back to their fat subterranean taproots by the end of summer. They will be gone before the firewood they conceal becomes useful again.
New bluish green growth regenerates vigorously at the end of winter, but does not bloom until early summer. The compound leaves are comprised of only a single pair of narrowly oblong leaflets with a branched tendril in between. Each leaflet is about two inches long and less than half as wide. Stems and petioles are winged. Once established, perennial pea can be difficult to eradicate.
Tony Tomeo 
I am trying to think about what our “frozen northern ” version of this would be. Obviously it’s not any of our truly noxious vines, although bittersweet might qualify if you saw it fruiting.
I think the closest thing we have is Virginia Creeper. It is spread readily by the birds, has lovely foliage, great fall color and a wonderful berry (which is how the birds spread it). But woe to you if you don’t get the vines out when they’re young!
Karla
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Oh my! It is nothing like that. Virginia creeper and Boston ivy grow on Freeway soundwalls to muffle sound and prevent graffiti, and because they are some of the few plants that color nicely in autumn. They are voracious. Perennial pea is voracious as a small perennial, but has its limits. It dies back annually, so does not get very far. Doesn’t it grow there? Harsh winters should not be a problem for it, since it dies back to the roots anyway.
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What a wonderful picture! We don’t see them much here anymore, and this reminds me of being at grandma’s house.
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I don’t remember them being as common as they are now. They were around when I was a kid, but only in a few spots on the main roads. Although they have not gotten far from where they were, they have spread out in the ditches and fence lines along those same roads.
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I like those! They make the roadsides look so festive! Can you imagine – if they had the same fragrance their garden variety cousins do, we would all grown them! We actually had them in this little house we had in Sweden. Before we moved in, I had never seen them before. I’m relaying this to say that not only are they tough – they are also hardy to at least Zone 5.
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Yes, that is a good way to describe it (although I would be embarrassed to use such fancy language as ‘festive’.) They are so abundant here right now that I think fragrance would be excessive.
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Cross my heart… I think a field of Dandelions is festive too. Maybe not the kind of party I want, but you can’t deny the cheery visual impact it has. There is one front yard just down the street from me, which fits that description. Yikes!
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In the 1960 and 1970s, someone plugged English daisy into lawns throughout Golden Gate Park in San Francisco. They are not uniform, but have developed into drifts, and are too traditional now to do anything about. Besides, I doubt anything could be done about them. I forget who did it, but it was someone who became famous for doing so. Dandelions go wild there too, although are not too terribly abundant. It is a great look.
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LOL – I’m going to have to look that guerrilla gardener up!
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I m sorry I do not remember the name.
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No worries. I bet Google does! 😊
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I have never been able to find who this mysterious person was. The professor who told us about him passed away years ago.
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Bummer… tried looking it up, but couldn’t find anything either. What a trickster, huh?
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When I saw your title I thought of our Senna hebecarpa, which is a perennial in the pea family with yellow flowers, really nothing like a sweetpea vine.
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I had to look that one up. It is related to the cassia trees that used to be more popular in Southern California. There are a few as street trees in Capitola. The really are striking in bloom, but supposedly to not last long, and are rather structurally deficient.
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