The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Altoona can be reffered to in order to determine 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.

You can plant nigella earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

The earliest that you can plant nigella in Altoona 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. If you are starting your nigella indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Altoona the average date of last frost happens on May 15. You should expect an average low temperature of -25°F in the coldest months of winter.

Since the USDA zone info for Altoona is an average the actual date of last frost is different every year. Half of the time in Altoona you get a frost after May 15 so make sure that you are prepared to cover your nigella if you have a late frost.

USDA Zone Info for Altoona

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 Altoona

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