Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of determining when to plant onions is to examine the USDA zone info for Windsor.

Planting Calendar for Onions

Frost tolerance for onions:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

You can plant onions much earlier in the year because they do well in cold.

The earliest that you can plant onions in Windsor is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant onions and expect a good harvest is probably October. Any later than that and your onions may not have a chance to really do well. If you are starting your onions indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Windsor. In the coldest months of winter you should expect an average low temperature of 25°F.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Windsor and it changes from year to year. Half of the time in Windsor there is a last frost after February 15 so just be sure to be ready to cover your onions if you have a late frost.

USDA Zone Info for Windsor

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Windsor

You may be interested in your other planting guides for Windsor.