The USDA Zone info is a great tool for gardeners to help us estimate your gardening 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 Willow Springs can 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.

Nigella tend to make it in quite a bit of cold which means that you can plant them earlier in the year than other frost tender plants.

The earliest that you can plant nigella in Willow Springs 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 grow to maturity. Starting your nigella indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

It's important to remember that USDA zone info for Willow Springs is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Willow Springs it frosts late in the year after April 15 so always be ready to protect your nigella if you have a late frost.

USDA Zone Info for Willow Springs

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 Willow Springs

You may be interested in your other planting guides for Willow Springs.