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.

The USDA zone info for Henderson can be used to estimate when it's the best time 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.

Since calendula do well in moderate cold you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant calendula in Henderson 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 fully mature. Starting your calendula indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Henderson the average date of last frost happens on April 15. It might get as low as -5°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Henderson is not always accurate and the actual date of last frost changes from year to year. Half of the time in Henderson you get surprised by a frost after April 15 so always be ready to protect your calendula in the event of a surprise late frost.

USDA Zone Info for Henderson

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 Henderson

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