One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Merced can be used to estimate when it's possible to plant welsh onion.

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.

Since welsh onion are barely cold tolerant you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant welsh onion in Merced 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. If you wait 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

On average all chance of frost has passed is on February 15 in Merced. You can expect an average low temperature of 20°F in the coldest months of winter.

Since the USDA zone info for Merced is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Merced you get surprised by a frost after February 15 be ready to cover your welsh onion if you have a late frost.

USDA Zone Info for Merced

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Merced

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