Many people ask how long do red onions take to grow, and that’s why we put together this guide and chart, so you can better understand all about the red onion.
The growing time of red onions (Allium cepa) is variable, but here we will explain all the stages of red onion growth.
How Long Do Red Onions Take to Grow – Diagram
The time it takes for red onions to grow is not very variable, it depends on the climate conditions of each place, available nutrients, and water. Also, if the red onion is affected by pests and diseases or weed problems, it will take more or less time to grow.
In the following image, you can see a diagram with the time it takes for red onions to grow in months:

On the other hand, red onions that were sown directly in the ground usually finish their cycle one month earlier than those that were repotted.
As expressed in point 3, the red onion is a biennial plant that goes through several stages throughout its cycle.
In this order, red onions germinate, then their roots and leaves develop, later the bulb becomes fat, then the leaves are dried and prepared for hibernation, at which time it is harvested for consumption.
Generally, the duration of the crop is about 5 months, but as we said, this will depend a lot on the environmental conditions and its genetics. Even so, we can’t expect it to mature much earlier than 5 months or much later.
Harvest time can be advanced or delayed slightly to coincide with good weather conditions. Learn more about When to Harvest Onions.
This can shorten or lengthen the growing time by several days or even a week or two. It is preferable to delay harvesting rather than advance it, so as not to harvest the red onions when they are still too green, which would result in poor storage. Learn more about When to Pick Red Onion.