Bonsai Jack - Black 1/4 inch Horticultural Lava Rock Soil Additive For Cacti, Succulents, Plants - No Dyes or Chemicals - 100% Pure Volcanic Rock (3.5 Gallons) EASY TO MAINTAIN -- Focus on the most satisfying part of maintaining a plant. Adding porous lava rocks instead of mulch to maintain plants like orchids, succulents, cacti, and bonsai trees ensures proper drainage while maintaining moisture. IDEAL DRAINAGE -- The porosity of lava rocks allows for excellent drainage while maintaining moisture within soil to allow your newly potted, acid-loving plants to cultivate and flourish CUSTOMIZABLE MIX -- Lava Rock is used as a soil additive or top dressing in the art of bonsai. Bonsai Jack lava rock soil additive can be mixed with ingredients such as pine bark fines, granite grit, calcined clay, and or dirt to create soil specific to your needs. MULTI-USE -- The temperature tolerance and quality of Bonsai Jack lava rocks make it useful for filling aquariums, ashtrays, fire media, garden soil amendment, fire pits, in addition to top dressing for plants. MADE IN THE USA -- All Bonsai Jack soil products are lab-tested, are not dyed, and are chemical free, unlike other brands that sell reclaimed organic matter which contain pathogens like nematodes and insects that can damage or kill plants.