Before planting it is a good idea to find your USDA Zone info to estimate 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 figuring out when it's a good idea to plant welsh onion is to refer to the USDA zone info for Mission.

Planting Calendar for Welsh onion

Frost tolerance for welsh onion:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Welsh onion are barely cold tolerant which tells us that you can start planting them slightly earlier than other frost tender plants.

The earliest that you can plant welsh onion in Mission is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant welsh onion and expect a good harvest is probably September. Any later than that and your welsh onion may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your welsh onion indoors.

Last Frost Date

The average date of last frost is February 15 in Mission. In the coldest months of winter you should expect an average low temperature of 25°F.

Remember that USDA zone info for Mission is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Mission there is a last frost after February 15 so make sure that you are prepared to protect your welsh onion if you have a surprise late frost.

USDA Zone Info for Mission

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 Mission

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