Longleaf need a few things in order to come out of the grass stage. the first thing is nutrients. if you have a longleaf (or any tree ) planted on the wrong site it will never reach its potential. second is plenty of sunshine. pine is a pioneer species, which means it in the first woody vegetation to grow in the sucessional stages of a forest and does not like competition with other species. you can create a good environment for longleaf by spraying chemicals or with the proper use of fire. longleaf love fire for several reasons, one being the fact that fire supresses all the surrounding competition allowing the tree to utilize most of the nutrients avaliable. the second is the control of brown spot needle blight. Longleaf are the most hardy, disease resistant of all the southern yellow pines, however the one that can get it is brown spot. by burning the trees every few years you can neutralize the threat of brown spot. now do not just go and burn your longleaf any time. One of the reasons this tree can survive fire at a young age is because the apical bud is covered by a tuft of needles, when a fire passes over the tree the bud is protected. in the late spring and early summer that but will shoot up and become exposed. if fire reaches the bud at this time the tree will be a gonner. late winter is the best time to burn young longleaf, whie the bud is protected. i have 80 acres of longleaf pine on my property, it is my most favoriate tree. I did my senior thesis on longleaf management at LSU. If you have specific questions PM me. I wish more people would get the longleaf bug. I will try and post some pics.