Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first opportunity to plant onions in Robstown can be determined by using the USDA zone info.

Planting Calendar for Onions

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

Onions do ok in quite a bit of cold which means that you can plant them much earlier in the year than other frost tender plants.

The earliest that you can plant onions in Robstown 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 grow to maturity. You can get started a couple of weeks earlier by starting your onions indoors.

Last Frost Date

On average the last frost has passed is on February 15 in Robstown. It might get as low as 25°F during the coldest months of winter.

Always keep in mind that USDA zone info for Robstown may not be accurate from year to year and the actual date of last frost will vary from year to year. Since half of the time in Robstown it frosts late in the year after February 15 be ready to protect your onions if you have a late frost.

USDA Zone Info for Robstown

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 Robstown

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