One of the best tools that you have as gardeners to help us figure out 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.

The earliest that you can plant nigella in Worthington should be figured out 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.

Nigella do ok in quite a bit of cold which means that you can plant them quite a bit earlier in the year than other frost tender plants.

The earliest that you can plant nigella in Worthington is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant nigella and expect a good harvest is probably August. If you wait any later than that and your nigella may not have a chance to really do well. You can get started a little bit earlier by starting your nigella indoors.

Last Frost Date

The average date of last frost is May 15 in Worthington. In the coldest months of winter you should expect an average low temperature of -25°F.

Since the USDA zone info for Worthington may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Worthington you get surprised by a frost after May 15 be ready to protect your nigella if you have one of those late frosts.

USDA Zone Info for Worthington

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°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 -20°F.

Plants to Grow in Worthington

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