One of the first steps you take when you are figuring out 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.

One way of estimating when to plant nigella is to look at the USDA zone info for Oregon.

Planting Calendar for Nigella

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

Nigella are very cold tolerant which means that you can get them planted much earlier than other frost tender plants.

The earliest that you can plant nigella in Oregon 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 really do well. 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 April 15 in Oregon. In the coldest months of winter you should expect an average low temperature of -20°F.

Since the USDA zone info for Oregon is just an average the actual date of last frost changes from year to year. Half of the time in Oregon there is a last frost after April 15 so always be ready to cover your nigella if you have a surprise late frost.

USDA Zone Info for Oregon

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Oregon

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