The USDA Zone info is a great tool for gardeners to help us estimate 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.

You will be able to determine when it's possible to plant calendula by checking out the USDA zone info for Louisville.

Planting Calendar for Calendula

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

Calendula do ok in mild cold which tells us that you can plant them a little bit earlier in the year than other frost tender plants.

The earliest that you can plant calendula in Louisville 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 grow to maturity. You can get started a couple of weeks earlier by starting your calendula indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Louisville. You can expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Louisville is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Louisville there is a last frost after April 15 be ready to protect your calendula if you have a late frost.

USDA Zone Info for Louisville

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 Louisville

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