Analyses of a number of leaf composts showed that the composts generally contain excessive salts. Greenhouse and laboratory observations suggest that when leaf compost is used in large proportions in a soil mix for container-grown plants, salts may damage young seedlings transplanted in the mix. Excess salts can be removed by leaching with liberal quantities of water before transplanting. Leaf compost is well-buffered at about pH 7, which is considered optimal for most plants. However, since leaf compost tends to resist acidification, it may cause the pH of mixes containing large amounts of compost to remain higher than that considered suitable for such plants as azalea, rhododendron and laurel.