I heard that if you need to use it for a walkway or a play area it is fine. But given that it is black, or at least dark, that it absorbs heat and can fry plants.

I bought some several years ago and love it. As of yet, it has not fried any of my plants. I bought the shredded kind, not the chunky style.

I'm buying more! It's still there 3 years later, didn't float off in hurricane Ike. I've got it around the pond but am sooooo happy with it I'm thinking of putting it in the whole yard. I mulch and 2 weeks later it's GONE! The heat/humidity/rain... The rubber mulch is still there. I'm most impressed with the fact that it stayed in place with 4' of salt water and stuff floating everywhere, including two huge cement pots that are about 3' tall and weigh over 100 pounds.
Tally HO!

It's not recommended for areas where you will be planting flowers and changing them from season to season. It will never biodegrade but it will get mixed into your soil when you are planting which is not good. It's great for pathways and areas where no more digging will be done if you like the look. Heating because it's black is not an issue...it doesn't conduct heat and it does come in colors other than black if you prefer. If it heated from the sun, it wouldn't be used in playground areas. I don't personally like the look of it, but it does great when it comes to lasting a long time . If you use it in areas where you will be doing any planting after it's installed, it will pretty much make the soil unusable for all living plants because it will disturb roots ability to grow and stay watered if it's mixed into the soil. I prefer to exclude anything which is inorganic in my plant and flower areas...I don't even like to use gravel, crushed rock, or river rock unless it's large and easy to remove. It will get squished into high traffic hyper-saturated gumbo clay soils which will be impossible to clean, but it sits well on more sandy or loamy types of soil. Good luck...