its anything used to lay over the soil really, dead leaves bark stuff like that the only use i know of is to stop the sun vapourising the water in the soil, dont use pine needles as they are very asidic

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The creator of The Eruption http://www.rollitup.org/toke-n-talk/62975-eruption.html
I will be starting to grow outdoor for the first time this year.
I will be making a growing journal.
Keep toking people