The Long Island Dahlia Society will hold a Dahlia Basics class at 7 p.m., on Thursday, April 17 in the Carriage House at the Bayard Cutting Arboretum on Montauk Highway in East Islip. In addition, there will be a preseason Dahlia tuber sale at 8 p.m. Refreshments will be served and admission is free. For information or directions, visit WWW.LongIslandDahlia.com or call Joe at 1-631-754-1002 in the evening or 832-3652 during the day.