One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Round Rock you can estimate when it's possible to plant nigella by referring to the USDA zone info.

Planting Calendar for Nigella

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

You can plant nigella earlier in the year because they do well in cold.

The earliest that you can plant nigella in Round Rock 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 nigella and expect a good harvest is probably September. Any later than that and your nigella may not have a chance to fully mature. You can get started a little bit earlier by starting your nigella indoors.

Last Frost Date

In Round Rock the average date of last frost happens on March 15. In the coldest months of winter you can expect an average low temperature of 15°F.

Keep in mind that USDA zone info for Round Rock is just an average and the actual date of last frost will vary from year to year. Half of the time in Round Rock last frost occurs after March 15 so make sure that you are ready to cover your nigella if you have one of those late frosts.

USDA Zone Info for Round Rock

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Round Rock

You may be interested in your other planting guides for Round Rock.