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.

By looking at the USDA zone info for Downingtown you will be able to figure out when it's possible to plant nigella.

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 tells us that you can start planting them much earlier than other frost tender plants.

The earliest that you can plant nigella in Downingtown 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 couple of weeks earlier by starting your nigella indoors.

Last Frost Date

In Downingtown the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -5°F.

Just be sure to remember that USDA zone info for Downingtown is not always accurate and the actual date of last frost is different every year. Since half of the time in Downingtown it frosts late in the year after April 15 be ready to protect your nigella in the event of one of those late frosts.

USDA Zone Info for Downingtown

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Downingtown

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