One of the best tools that you have as gardeners to help us determine 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.

You will be able to determine when it's possible to plant black radish by looking at the USDA zone info for Harlingen.

Planting Calendar for Black radish

Frost tolerance for black radish:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant black radish a little earlier in the year because they do well in moderate cold.

The earliest that you can plant black radish in Harlingen 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 black radish and expect a good harvest is probably October. If you wait any later than that and your black radish may not have a chance to fully mature. Starting your black radish indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Since the USDA zone info for Harlingen is not always accurate the actual date of last frost is different every year. Half of the time in Harlingen you get a frost after February 15 so always be ready to cover your black radish in the event of one of those late frosts.

USDA Zone Info for Harlingen

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 Harlingen

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