plants and plant extracts: for example arnica, aloe, beard lichen, ivy, stinging nettle, ginseng, henna, camomile, marigold, rosemary, sage, horsetail or thyme; animal extracts: for example royal jelly, propolis, proteins or thymus extracts; ...
Using Perlite in Potted Plants--by George (Doc) and Kay AbrahamOld article but still very helpful. How to Handle Tip BurnAnother old but very helpful article. Cultivation of Spruce Seedlings in Mixtures of Perlite and Sphagnum Peat in Norway ...