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 first chance to plant nigella in Irmo can be estimated by reviewing 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.

Since nigella do well in cold you can plant them a lot earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant nigella in Irmo 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. If you are starting your nigella indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Irmo the average date of last frost happens on March 15. It might get as low as 10°F during the coldest months of winter.

Since the USDA zone info for Irmo is not always accurate the actual date of last frost changes from year to year. Half of the time in Irmo it frosts late in the year after March 15 so make sure that you are ready to cover your nigella in the event of a surprise late frost.

USDA Zone Info for Irmo

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Irmo

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