The periwinkles genus, commonly referred to as Periwinkles, generally requires bright light, moderate watering, and warm temperatures. These plants prefer well-draining, rich soils. Common challenges include pests such as aphids and fungal diseases like root rot, often due to overwatering or poor air circulation. As for seasonal considerations, they flourish in the summer but need protection in winter in colder zones, whilst reduction in watering is necessary in autumn. Regular monitoring and appropriate adjustments to care based on seasonal changes are key for healthy plants.