Technical Abstract: Moisture characteristic curves (MCC) relate the water content (') in a substrate to the matric potential ('m) at a given tension or height (h). Most techniques for developing MCC are not well-suited coarse substrates such as those composed of bark used in container nursery substrates. The objectives of this research were to compare an inexpensive modified Long Column (MLC) method to an established method for creating low tension MCCs, and then to determine the best model for describing MCCs of bark based soilless substrates. Three substrates composed of Douglas fir bark alone or mixed with either peat moss or pumice were used to compare models. Both methods described differences between the three substrates, although MCC for each method differed within a substrate type. A four parameter log-logistic function was determined to be the simplest and most explanatory model for describing MCC of bark based substrates.