You are referring to what is called mulch, cedar or pine bark mulches to be exact. It doesn't matter what colour works best, choose the colour you'd prefer. Mulch works to maintain moisture, keep temperatures steady and also to suppress weeds. you'll have to use aged wood chips to do this otherwise fresh ones can rob the ground of nitrogen which is detrimental to plants.

However mulches (whether wood or stones) will not be able to suppress weeds for too long. It can kill weeds beneath it and prevent weed seeds from growing, but it cannot prevent new weed seeds from growing on top of it. The way to tackle any new growth is simply to disturb mulch with a rake or hoe when the weeds are young and usually this is enough to kill off new weeds. - but to make a point on how persistent weeds can be, a dandelion for example will find a way to grow in aspalt.

The way to apply the mulch is to put down weed cloth which is usually black and then top with the mulch. Don't use a poly sheet which is shiny and not porous. You can get weed cloths at hardware stores. Weed cloths need to be porous so the plant can still receive water.

Eventually though weed cloths can deteriorate and require replacement. Hope this helps..

It does everything ianna but keeping moisture in and weeds down is HUGE! I prefer pine bark fines and no landscape fabric. Reason for this is that with the landscape fabric it is a lot harder to add things to your soil. As well I want the real fine bark to break down (compost) to add tilth and organic matter to my soil. The places you mention usually use landscape fabric and cedar mulch to keep it as low maintenance as possible.

SCG

Hi, Some do enjoy just layering down mulch direct to the ground. I do prefer though to lay down a weed cloth which helps to prevent some weed seeds from reaching the earth beneath.-- However dandelions can be very persistent.

There's a good point though made regarding moisture. the problem with mulch is that it prevents light rain from reaching the roots of the plants. the way around this is to make sure you make space just around the plant and to water very deeply once or twice a week. Once watered, the mulch will keep the plant moistened for longer periods.

Oh,, and just because you've put down mulch, doesn't mean you cannot add new soil because you can.. you just need to move the mulch aside and topdress your soil. It will make for a healthy plants.

I agree, dandelions can be very persistent. I wasn't very clear in my other post about why I choose to use bark fines and weed control. The fines form more of a mat not letting weed seeds to get to the ground. The coarser the mulch the more likely seeds can fall between mulch pieces and get to earth. A common problem people have is not putting enough mulch down. The coarser the mulch the thicker it needs to be. With fines you can get away with 2-3" really coarse stuff your going to want 5-6". The few weed seeds that do germinate are extremely easy to pull with methods described by ianna. If you use a landscape fabric you can use a lot less mulch. Just be sure to use enough so the suns rays can't get to the fabric. UV rays are what breaks landscape fabric down. BTW this isn't based on my experience it came from a landscaping buddy. Following his advice on using fines I water less than half the amount the bed that does have mulch. I also have maybe spent a whopping ten minutes weeding opposed to hours a week in the other.