Transit Point by A.S. Webster
Anna Pendress is the child of colonists on a world where her ancestors crash-landed centuries before. A world where seasons last over six standard months, including the bitterly cold winters. Lucas Bradford is a young Explorer in the Galactic Service, specializing in xenobotany assigned to explore that world.
Lucas is fascinated by the plant life adapted to survive on this world and he befriends Anna to help him with his work. Not willing to give information away freely, Anna trades him knowledge for knowledge. She demands answers to questions that none of her fellow colonists have been able to answer. They exchange skills and forge a friendship that lasts over years.
The Explorers are looking for planets able to hold the excess population of the inner planets and the colonists need to regain lost technology quickly to hold what they have. Together, Anna and Lucas must make decisions that will not only affect themselves, but every colonist on her planet.