The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of getting a good idea when it's the best time to plant calendula is to refer to the USDA zone info for Ripon.

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 Ripon 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 fully mature. If you are starting your calendula indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Ripon. In the coldest months of winter you can expect an average low temperature of -20°F.

It's important to remember that USDA zone info for Ripon is not always accurate and the actual date of last frost changes from year to year. Since half of the time in Ripon last frost occurs after April 15 be ready to protect your calendula if you have a surprise late frost.

USDA Zone Info for Ripon

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Ripon

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