Manure, especially that of domestic animals, cows, sheep and chickens, is the oldest fertilizing agent known to man. and has been used to help plants grow ever since the first farmer cultivated his crops. The problems involved with using manure as a fertilizer on house plants are pretty much the same as those discussed in the previous chapter on potting soil; it is bulky, difficult to store, and has a smell that many people find extremely offensive. Further, it is not particularly efficient in the small doses required by the space limitations in a house plant garden. Due to its non-concentrated form large quantities are needed and must be worked into the soil by hand. Many people recommend that the home gardener use as his feeding agent liquid manure. This is a solution made by steeping a bag of cow manure in water. The mineral nutrients contained in the manure are dissolved in the water, and the result is a strong solution, which can be diluted with water and used to feed the plants. Here again, most people will have the problem of providing space (here, too, a cellar or barn seems to us the only answer) and taking the time needed to make this concoction. We feel that the solution for most people is to be found in commercially prepared plant foods.