Using pebbles or stones underneath your plants though has more disadvantages than advantages, in my point of view. When you use stones, make sure that it is exactly what you want. If you change your mind after spreading a ton of pebbles underneath all your garden plants, who is going to pick them up to get rid of them when you change your mind six months later? My suggestion is that you use organic mulch first and then work your way to rocks if your garden is new. Established, full-grown plant gardens can be easier to define exactly where you want to use pebbles and you won't be apt to change your mind after you have them down. Rocks and stones will also create hotter environments around plants, which will need more watering and may wilt easier in the summer heat.
Rubber mulch is the latest innovation in mulches on the gardening scene, again, with its pros and cons. The value of rubber mulch is that it's a pervious surface, allowing water to drain into the earth, replenishing ground and surface water, and it's not attractive to insects. Rubber mulch is also an excellent groundcover for parks, children's playgrounds, parking lots, and personal car and boat common areas. It is a softer surface so if you are concerned about children hurting themselves, this is an excellent choice but make sure you buy the better quality rubber and not the cheap rubber mulch which still has protruding metal in it. With rubber mulch, you want quality. It's also a permanent alternative, not needing replacement, so make sure it's what you ultimately want. Rubber mulch has the distinct advantages of having hundreds of rainbow choices to select with blues, purples, greens, pinks, yellows, and oranges.
I have seen a homeowner's landscape mulched with teal blue rubber around his tropical plants; it not only was colorful but also gave me a feeling of Caribbean ocean coolness that you would not get with wooded mulches. If you have a pool landscaped terrace, tropical colored mulch would add to the festive surrounding. The disadvantages of rubber mulch are few, but there are some. Mostly it's the aestethics of using rubber - you may not want to use artificial mulch in your organic landscape. Costs are also higher than organic mulches but then you don't have to pay to replace it every year either. The other point is that the color may affect the temperature of the rubber. Dark colors will absorb heat more readily than lighter shades. As with dyed organic mulches, be careful using colored mulches in your design as it may camouflage your flowers rather than highlight them.
