One of the best tools that you have as gardeners to help us figure out 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 Harwood Heights it's possible to estimate when 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 tend to make it in pretty solid cold which tells us that you can plant them much earlier in the year than more sensitive plants.

The earliest that you can plant nigella in Harwood Heights 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. If you wait any later than that and your nigella may not have a chance to fully mature. 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 Harwood Heights. It might get as low as -15°F during the coldest months of winter.

Always keep in mind that USDA zone info for Harwood Heights is an average and the actual date of last frost changes from year to year. Since half of the time in Harwood Heights you get a frost after April 15 be ready to cover your nigella if you have a late frost.

USDA Zone Info for Harwood Heights

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Harwood Heights

You may be interested in your other planting guides for Harwood Heights.