ground covers, how do they work?

pdxmouse

I grew up with mostly shrubs and a veggie garden, so we never really used ground covers. Mulch, sometimes. So school me. If I buy a ground cover and let it spread around, will it really keep the weeds at bay? Or at least hide them a bit? If I plant them where my perennials are, will it choke them out or not let them poke through in spring?

I don't much care if it all stays where it "should" as long as it doesn't take over other plants and I'm not finding it 3 blocks away in the nature corridor.

~NB~

Every plant is different. Everything that gets called "groundcover" doesn't have the same growth habit. Some of them choke out competition more than others. Some grow in a dense, thick mat. Some are viney. Some like shade, some like sun. Some like wet, some like dry. Some of them have pretty flowers. Some are evergreen. Some throw seeds far and wide. Some tolerate occasional foot traffic.

But they are all different, so there isn't ONE answer that applies across the board.

living_insanity

We dont have our ground cover plants anywhere near my perennials.

We have it underneath some azalea bushes and we have some around our oak tree because it was impossible to move around the tree so we dug an area out around the tree and added some ground cover.  

 

We have phlox under the azaleas and something that's is mostly just pretty leaves for the oak tree.  DH picked it out and I have no idea what it is.  We started with two plants of everything so they can spread out and eventually meet

pdxmouse

~NB~:

Every plant is different. Everything that gets called "groundcover" doesn't have the same growth habit. Some of them choke out competition more than others. Some grow in a dense, thick mat. Some are viney. Some like shade, some like sun. Some like wet, some like dry. Some of them have pretty flowers. Some are evergreen. Some throw seeds far and wide. Some tolerate occasional foot traffic.

But they are all different, so there isn't ONE answer that applies across the board.

Okay. So if I search might I find one that will still let the dahlias or peonies (biggest problem spots) through? Is there a good way to find out if something is likely to go invasive/weedy/serial killer? When they warn that it creeps over borders, do they really mean "will devour your yard"? I already have a patch of mint from the previous owners that I have to pull up every year. If it doesn't form a dense (choking?) mat is it any good at keeping down the weeds, or does it just look pretty?

The ones I've seen that I like the best are bugleweed, mazus reptans, and the creeping thymes or corsican mint. I also like oxalis and lady's mantle but those seem like they might be troublesome. I have both sun and shade, mostly dappled sunlight. I'm PNW, so some things that are invasive in warmer climates seem to be okay here (and the reverse too). 

TootsieK

We have a lot of pachysandra, which forms a thick mat rather quickly, but doesn't stray too outrageously.  There's also periwinkle (vinca) in our yard, which grows more slowly but forms a dark-green mat with beautiful light purple-blue flowers in the spring.  Both of these are evergreen here (when you can see them through the snow).  There may be some minimal weeding with these, but after they form the mat, it's hard for weed seeds to germinate (no light).

I haven't had much luck with creeping thyme here, although I did in Colorado.  I think it likes a drier climate than we have here.

~NB~

I would just mulch around the perennials. If you really want to plant groundcover around them, I don't think that Mazus or Ajuga will ever prevent your Dahlias or Peonies from emerging.

Mazus needs consistantly moist soil. Ajuga can tolerate drier conditions as well as sun (my neighbor has Bugle Weed all over her sunny, dry front yard).

And yes, when they say it creeps over borders that usually is a way of understating an unpleasant truth.

CollegeGrrl219

My neighbors have some sort of creeper that spills over borders. They just prune it back every year.

Inkful

I'm in the PNW too. Sunset magazine has been a great resource- have a look at their plant finder http://plantfinder.sunset.com/sunset/plant-home.jsp.  Your local master gardener program would have advice too; in our area, they have a booth at the farmer's market.