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.

The USDA zone info for Tolleson should be reffered to in order to figure out when it's a good idea to plant nigella.

Planting Calendar for Nigella

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

Since nigella do well in cold you can plant them quite a bit earlier in the year than more sensitive plants.

The earliest that you can plant nigella in Tolleson 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 nigella and expect a good harvest is probably October. Any later than that and your nigella may not have a chance to grow to maturity. Starting your nigella indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost has passed is on February 15 in Tolleson. You should expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Tolleson is just an average the actual date of last frost changes from year to year. Half of the time in Tolleson you get a frost after February 15 so always be ready to cover your nigella in the event of a surprise late frost.

USDA Zone Info for Tolleson

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 Tolleson

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