The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to determine when to plant nigella by using the USDA zone info for Sullivan.

Planting Calendar for Nigella

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

Since nigella are one of those plants that can tolerate quite a bit of cold weather you can plant them much earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant nigella in Sullivan 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 fully mature. You can get started a little bit earlier by starting your nigella indoors.

Last Frost Date

On average the last frost is on April 15 in Sullivan. In the coldest months of winter you can expect an average low temperature of 5°F.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Sullivan and it will vary from year to year. Since half of the time in Sullivan you get surprised by a frost after April 15 be ready to protect your nigella if you have a late frost.

USDA Zone Info for Sullivan

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Sullivan

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