How to use worm castings in a soil mix? Worm castings can be used in a multitude of ways - mixed into a soil mix, a soilless mix, or as a tea or slurry. Usually worm castings is thought of as an additive. Recommendations vary wildly, but I would recommend adding one tenth to one fifth in any organic mix (10-20%). Top dressing with worm castings would work well, too, especially with indoor containers. Making a worm castings tea by steeping the castings in clean well aerated water makes for a life giving plant-nutrient. I recommend filtering worm tea before use and returning the dregs into the worm bin after a couple of rounds. One can use plain worm castings as a growing medium, and in my experience it works very well. But usually finished worm castings tends to be mud-like in consistency, and needs something to aerate and lighten up the texture. Perlite and expanded clay work very well for this. 50% of expanded clay (multiple size) and 50% worm castings makes for a nice quick-n-dirty primo soil(less) mix. The Classic Shabang Mix "The mix that I recommend is basically nothing but castings and drainage. I used to cut it with all sorts of things, including soilless peat-based mixes like pro-mix.. but then you're introducing a source for pH problems-- especially when others try and duplicate it but can't find the right brands then substitute with a peat-mix that is too acidic. So down to the bare basics of a mix: 40% castings 30% perlite 30% vermiculite" Quoted from GrowFAQ #781 here: 781.htm 102% Hyper Veg Mix by Aallonharja * 25% coco peat * 25% expanded clay * 50% worm casting * 2% alfalfa meal pellets * 1/4 tablespoon of dolomite lime per liter (1 per gal) * lemon juice (or 8% citric acid solution) * seaweed extract according to taste * silicon nutrient additive Note: - This is a guideline, not a recipe. Know your ingredients! - If things get too sticky, muddy or water retaining with the worm castings, add more coco peat, peat, perlite or expanded clay. - The stretching due to alfalfa can last up to 5 or more weeks. - For alfalfa meal pellets 2% is a careful estimate. More can be used if the plants can take it. - This mix should last about 4 weeks, ie. supply the plant with nutrients during the vegetative period, PK and N+Mg+Ca additive may be needed in bloom. Meek Flowering Mix * Worm castings, from bin fed with fruit and vegetables and peels (High K, Medium P) * Optionally in the first 4 weeks of flowering, add as needed: Pinch of dolomite lime or epsom salts Pinch of gypsym Pinch(es) of clean, pure wood ash Mix in a bucket of water, and filter solids. Water during flowering. Note: - This is a guideline, not a recipe. Know your ingredients! - Yields very vivid aromatic tones - Basically a high K + P + Mg + Ca + S solution - all thats needed in bloom. - N supplementation may also be necessary. Oh also, you could talk a bit about Casting Tea aswell. Well I've usually simply spooned some more or less finished castings into a cheapo nylon stocking and dumped that in a bucket and a reservoir. A surefire way would be using 100% finished worm castings with a high quality filter material, and place that in a bucket with water, aerate the water for 48 hours, and then use that water for watering, provided it didnt contain visible pests and didnt smell like rotten fish (aerobic teas shouldnt smell bad in the first place).