One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of estimating when it's possible to plant nigella is to check out the USDA zone info for Green River.

Planting Calendar for Nigella

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

Since nigella do well in cold you can plant them quite a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant nigella in Green River is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant nigella and expect a good harvest is probably August. If you wait 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 couple of weeks earlier.

Last Frost Date

In Green River the average date of last frost happens on May 15. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Green River is an average the actual date of last frost will vary from year to year. Since half of the time in Green River you get surprised by a frost after May 15 be ready to protect your nigella in the event of a surprise late frost.

USDA Zone Info for Green River

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Green River

You may be interested in your other planting guides for Green River.