Pyracantha grows best in full sun. While they are drought tolerant once established regular irrigation - say 4 to 5 gallons of water a week will help it to grow. If it were my shrub I would fertilize it with an organic fertilizer such as Holly Tone according to package directions. I fertilize my shrubs after they have gone dormant. Mulching it with organic materials will also help feed the soil as it breaks down. Best And Happy Yardening, Nancy.