One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Stone Park you can figure out when it's the best time to plant nigella 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 are very cold tolerant which tells us that you can start planting them much earlier than more sensitive plants.

The earliest that you can plant nigella in Stone Park 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 really do well. Starting your nigella indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Stone Park. You can expect an average low temperature of -15°F in the coldest months of winter.

Always keep in mind that USDA zone info for Stone Park may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Stone Park you get a frost after April 15 so be sure to be ready to cover your nigella in the event of a surprise late frost.

USDA Zone Info for Stone Park

Here is the info for USDA Zone 5b.

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

Plants to Grow in Stone Park

You may be interested in your other planting guides for Stone Park.