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

It's possible to estimate when it's possible to plant nigella by reviewing the USDA zone info for Rifle.

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 pretty solid cold which tells us that you can plant them a lot earlier in the year than other plants that might not handle the cold.

The earliest that you can plant nigella in Rifle 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. If you wait any later than that and your nigella may not have a chance to really do well. You can get started a few weeks earlier by starting your nigella indoors.

Last Frost Date

On average the last frost is on April 15 in Rifle. It might get as low as -15°F during the coldest months of winter.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Rifle and it changes from year to year. Since half of the time in Rifle it frosts late in the year after April 15 be ready to cover your nigella in the event of a late frost.

USDA Zone Info for Rifle

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 Rifle

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