Flower Fields Ranunculus Tours. Every year from early March to early May, The Flower Fields at Carlsbad Ranch blossom into a spectacular sea of brightly colored ranunculus flowers. Visitors can view and tour the fields in Carlsbad. Open to the public seven days a week, 9am to 6pm. Interstate 5 to Palomar Airport Road Exit. Head east one block and turn left on Paseo Del Norte. Make a right into the first driveway. Guided tours must be arranged in advance.