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

A common way of determining when it's the best time to plant zinnia is to consult the USDA zone info for Imperial.

Planting Calendar for Zinnia

Frost tolerance for zinnia:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since zinnia are not cold tolerant you really should wait until after the last frost before you can plant them.

The earliest that you can plant zinnia in Imperial 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 zinnia and expect a good harvest is probably September. Any later than that and your zinnia may not have a chance to really do well. Starting your zinnia indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on January 31 in Imperial. You should expect an average low temperature of 30°F in the coldest months of winter.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Imperial and it can change quite a bit from year to year. Half of the time in Imperial you get a frost after January 31 so always be ready to protect your zinnia in the event of one of those late frosts.

USDA Zone Info for Imperial

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Imperial

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