The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to determine when to plant nigella by using the USDA zone info for Keene.

Planting Calendar for Nigella

Frost tolerance for nigella:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

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

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

Last Frost Date

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

Since the USDA zone info for Keene is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Keene last frost occurs after March 15 be ready to cover your nigella if you have a surprise late frost.

USDA Zone Info for Keene

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 Keene

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