One of the first steps you take when you are estimating 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 Harrison you can figure out when it's the best time to plant nigella by looking at 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.

You can plant nigella quite a bit earlier in the year because they are very cold tolerant.

The earliest that you can plant nigella in Harrison 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. You probably don't want to wait any later than that or else 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

In Harrison the average date of last frost happens on April 15. You should expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Harrison is an average the actual date of last frost will vary from year to year. Since half of the time in Harrison you get a frost after April 15 be ready to protect your nigella if you have a surprise late frost.

USDA Zone Info for Harrison

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°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 -5°F.

Plants to Grow in Harrison

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