[header] How to apply a poultice [title] Grind roots, seeds and other hard herbs in a coffee grinder or mortar and pestle. [substeps] You may use fruits and vegetables in poultices, too. These are usually grated instead of ground. 
Already-fine herbs and powders don't need to be ground. [title] Mix the ground or dried herb with a bit of oil or water until it forms a moist paste.