over the past couple years ive bought several 3'/4' white pine trees in the spring to plant in my yard and a few have died so this year i kept the burlap bag wrapped around the root ball (just removed the nails holding bag closed) hoping that by not disturbing the soil packed around the roots the plant shall do better . is this gonna work or do i have to cut down into the soil with a big knife and put some cuts in the burlap ?