The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Alpine you should be able to estimate when it's a good idea 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 do well in cold which means that you can plant them much earlier than more sensitive plants.

The earliest that you can plant nigella in Alpine 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 fully mature. You can get started a few weeks earlier by starting your nigella indoors.

Last Frost Date

On average the last frost has passed is on March 15 in Alpine. In the coldest months of winter you can expect an average low temperature of 10°F.

Since the USDA zone info for Alpine is just an average the actual date of last frost is different every year. Since half of the time in Alpine you get surprised by a frost after March 15 be ready to cover your nigella in the event of a surprise late frost.

USDA Zone Info for Alpine

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Alpine

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