Canadian grown. The red onion (Allium cepa) is a variety of onion known for its vibrant red or purplish skin and mild to sweet flavor. It is a popular choice in various culinary dishes, adding color and a subtle taste to salads, sandwiches, and other recipes. Red onions can be grown from seeds, sets, or transplants, and they thrive in well-drained soil with plenty of sunlight. In a greenhouse setting, you can start red onion seeds indoors before transplanting them to the garden or continue growing them in containers.