Sun Bulb 5011 Better-Gro Phalaenopsis Mix, 8 Quarts Phalaenopsis mix It is a fertile mixture of Canadian chunk peat blended with western fir bark, hardwood charcoal and coarse perlite It is developed to provide the proper mixture of fertilizer and moisture needed to encourage superior phalaenopsis plant and root growth Provides your phalaenopsis orchids with the drainage, air flow, and root ventilation they find and thrive on in nature It should be used when re-potting your orchid, at least every 12-18 months or as needed to support healthy growth