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

In Sierra Vista you can figure out when it's a good idea to plant zinnia by referring to the USDA zone info.

Planting Calendar for Zinnia

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

Since zinnia do not do well in cold weather you need to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant zinnia in Sierra Vista is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant zinnia and expect a good harvest is probably August. If you wait any later than that and your zinnia may not have a chance to fully mature. Starting your zinnia indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is March 15 in Sierra Vista. In the coldest months of winter you can expect an average low temperature of 15°F.

Since the USDA zone info for Sierra Vista is just an average the actual date of last frost will vary from year to year. Since half of the time in Sierra Vista there is a last frost after March 15 be ready to cover your zinnia if you have one of those late frosts.

USDA Zone Info for Sierra Vista

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

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

Plants to Grow in Sierra Vista

You may be interested in your other planting guides for Sierra Vista.