Invasive perennials (periwinkle, sweet pea)?

Was considering a variety of different plants for attempting a hard to grow garden in the shade.
The area is zone 6, with dry, rocky hard soil, and a lot of shade from large trees (pine, maple, etc.) upstate, NY area.

-Will plants that are considered invasive, periwinkle for ground cover or sweet pea perennial vine on a back fence, present a problem by spreading all over? Am I asking for trouble?




This message was edited May 3, 2009 9:20 AM

One person's "invasive" is another person's "spreading with no trouble." I'm in z. 6 too, and have had both plants you mention in your post, I got rid of the perennial sweet pea - it outgrew its spot (way too small, I was thinking more of the annual sweet pea's size) and was not fragrant. BUT, it was quite easy to totally get rid of it using just fingers and a spade. No returning shreds next season like with chameleon plant or other scary invasives.

The other one you mentioned, periwinkle, or vinca, is one I adore but my husband does not. If it were up to me, all our hard-to-mow spots would have vinca instead of grass. I tried to establish a large colony IN the grass and he tried to eradicate it - again, just by mowing over it or pulling it up. Now I have enough to satisfy me in pots in my container garden.

My point is that neither of the two plants you mention are the types which become impossible to eradicate, should you change your mind after three - five years. They won't invade your grass or your neighbor's vegetables. Does that help?

Thanks for the reply, it does help.

Last year we set up a large planting area in the backyard up against the back fence. A sort of raised bed with stones making the border (around 81/2' deep and 20' wide). Some things didn't do too well in this difficult space. This year I figured on trying a variety of shade plants and seeing what does well (still making the selections of these). Was concerned the invasives might make it even harder for the other "trial plant" selections to make it. One thing that did grow was weeds, even though we mulched. I was hopeing a combination of different ground covers would cut down on the maintainence.

Thinking of Thymus p. cocconeus(creepng thyme, walk on me plant, mother of thyme) towards the front, Sedum spurium "fulda glow" (creeping red sedum) middle area, and vinca minor (periwinkle) towards the back fence. Front to back, smallest to highest ground covers, in hues of red then the periwinkle blue flowers back at the fence.

The sweet pea supposedly does well in shade, have that add some interest to the stockade wood fence.



This message was edited Apr 2, 2009 6:37 PM

This message was edited Apr 2, 2009 6:41 PM

My sweet pea took a few years to really get going in a similar situation. I haven't tried the sedum as a ground cover - I think I probably have it in a container somewhere. Mulch is not actually helpful against weeds, we've found. Try thick layers of newspapers under the mulch, you can even cut holes in it to plant through if necessary. This will break down, decompose and contribute to the soil health.

I use the newspaper method, too, with much better results than just mulch. My periwinkle behaves nicely in the shade, it is a favorite of mine, and I have other plants that come up through it with no problem.

Don't know the sweet pea.
I don't plant periwinkle in any mixed perennial beds, but haven't had any trouble getting rid of it. As said above, easy to eradicate (manually).

My biggest complaint with the sweet pea is that it had no fragrance! It made a great cut flower, grew nicely once established, it just wasn't "sweet". It also looks and feels a lot tougher and not as delicate and lovely as the annual sweet peas.

Most sedums do best in full sun, though I haven't grown sedum spurium- it might do fine there. Especially if you are going to use the newspaper to block the weeds, make sure the soil underneath will drain really well. The newspaper will hold in a lot of moisture. Sedums are mostly study, easy plants, but they will rot with wet feet.