Before planting it is a good idea to find your USDA Zone info to figure out 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 it's the best time to plant onions is to check out the USDA zone info for Colton.

Planting Calendar for Onions

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

Since onions are very cold tolerant you can plant them earlier in the year than other plants that might not handle the cold.

The earliest that you can plant onions in Colton 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. If you wait any later than that and your onions may not have a chance to fully mature. You can get started a few weeks earlier by starting your onions indoors.

Last Frost Date

The average date of last frost is February 15 in Colton. You can expect an average low temperature of 25°F in the coldest months of winter.

Keep in mind that USDA zone info for Colton is just an average and the actual date of last frost is different every year. Half of the time in Colton it frosts late in the year after February 15 so just be sure to be ready to protect your onions if you have a surprise late frost.

USDA Zone Info for Colton

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 Colton

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