Longleaf pine is being restored across its original range, but little information is available regarding the response of longleaf pine to soil water, bulk density, and fertility gradients. In comparison, much is known about loblolly pine across this range. In this study, we grew loblolly and loblolly pine seedlings for 13 weeks in small pots treated to create a 7 x 7 response surface of soil water content and bulk density. In addition, we repeated the study with fertilized soils to determine how soil fertility affected pine growth across this soil water content and bulk density response surface. We measured seedling root length density, root weight, and to weight of all seedlings and fit these data to response-surface regression equations with categorical variables for species and fertility.