Petunias can tolerate relatively harsh conditions and hot climates. They need at least five hours of sunlight every day. They grow well in low humidity, moist soil. Young plants can be grown from seeds. In drier regions, the plants should be watered daily. Maximum growth occurs in late spring.Do not expose the plants to heavy rains. A single heavy rain is capable of damaging the plant. Petunias are generally insect pollinated.