I have a small (less than 100 sq ft) indoor atrium which we have had for 18 years......the soil is covered with I was told when we did this that the wood chips on top of the soil have to be sterile.....We have never had any bugs........The soil has sunk over the years and I want to ad more wood chips.......do they have to be sterile......if yes where do you get sterile wood chips.......I have searched everywhere..HELP

to NGA

I don't have an atrium so can't answer the question but it seems that even sterile chips will end up with bugs or mushrooms eventually. How about rubber chips? Or putting down pavers?

I agree, unless you keep it entirely dry and free of plants or anything else, the wood chips will not be sterile for very long. If you've had that atrium for 18 years and never seen a bug or a fungus, something's being done to prevent them.

Does somebody take care of the atrium for you? Maybe they spray the wood chips with fungicide and insecticide regularly? If so, then you can just go ahead and get some new bagged wood chip mulch and put it down, then let your maintenance crew know to spray the next time they come. Rubber chip mulch smells rubbery for months and months after you lay it down. You don't want that in your house. Stones would be the cleanest mulch you could put down, but they're heavy, expensive and if you have plants planted in the soil in there, the stones are not a good mulch for plants. They tend to heat up the soil instead of cooling it down, and don't insulate well or retain moisture either.

Are plants growing in the soil under the old wood chips? Your atrium sounds really cool. If you're able to post a pic, I'm sure I'm not the only one who would enjoy seeing it.