One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for San Jacinto should be used to determine when it's possible to plant zinnia.

Planting Calendar for Zinnia

Frost tolerance for zinnia:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Zinnia require warm weather which means that you really should wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant zinnia in San Jacinto is March. However, you really should wait until April 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. You probably don't want to wait any later than that or else your zinnia may not have a chance to grow to maturity. Starting your zinnia indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is February 15 in San Jacinto. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for San Jacinto is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in San Jacinto you get a frost after February 15 so make sure that you are prepared to cover your zinnia if you have a surprise late frost.

USDA Zone Info for San Jacinto

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in San Jacinto

You may be interested in your other planting guides for San Jacinto.