Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Hillsboro should be used to figure out when it's possible 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 earlier in the year than more sensitive plants.

The earliest that you can plant nigella in Hillsboro 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. You probably don't want to wait any later than that or else your nigella may not have a chance to really do well. Starting your nigella indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Hillsboro. You should expect an average low temperature of 15°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Hillsboro is not always accurate and the actual date of last frost will vary from year to year. Half of the time in Hillsboro there is a last frost after March 15 so be sure to be ready to cover your nigella if you have a surprise late frost.

USDA Zone Info for Hillsboro

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 Hillsboro

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