One of the first steps you take when you are getting a good idea your gardening schedule is find your 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.

You can estimate when it's the best time to plant nigella in Riverton by checking out 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.

Nigella are one of those plants that can tolerate quite a bit of cold weather which means that you can plant them much earlier than other frost tender plants.

The earliest that you can plant nigella in Riverton 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 really do well. You can get started a couple of weeks earlier by starting your nigella indoors.

Last Frost Date

The average date of last frost is May 15 in Riverton. You can expect an average low temperature of -25°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Riverton and it is different every year. Half of the time in Riverton last frost occurs after May 15 so make sure that you are prepared to protect your nigella if you have one of those late frosts.

USDA Zone Info for Riverton

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 Riverton

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