One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By checking out the USDA zone info for Harwood Heights you will be able to determine when to plant calendula.

Planting Calendar for Calendula

Frost tolerance for calendula:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Calendula are moderately cold tolerant which tells us that you can plant them a little bit earlier than plants that are more sensitive to the cold.

The earliest that you can plant calendula 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 calendula and expect a good harvest is probably September. If you wait any later than that and your calendula may not have a chance to really do well. You can get started a couple of weeks earlier by starting your calendula indoors.

Last Frost Date

The average date of last frost is April 15 in Harwood Heights. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Harwood Heights is just an average the actual date of last frost will vary from year to year. Half of the time in Harwood Heights there is a last frost after April 15 so always be ready to cover your calendula in the event of one of those late frosts.

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.