One of the best tools that you have as gardeners to help us estimate 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.

You will be able to figure out when it's the best time to plant calendula by referring to the USDA zone info for Dover.

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 means that you can plant them a little bit earlier than other plants that might not handle the cold.

The earliest that you can plant calendula in Dover 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. Any later than that and your calendula may not have a chance to grow to maturity. Starting your calendula indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Dover. You should expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Dover may not be accurate from year to year the actual date of last frost changes from year to year. Half of the time in Dover you get surprised by a frost after April 15 so be sure to be ready to protect your calendula in the event of a late frost.

USDA Zone Info for Dover

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Dover

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