Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant tall phlox in Sierra Vista should be determined by looking at the USDA zone info.

Planting Calendar for Tall Phlox

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

Tall Phlox do well in mild cold which tells us that you can plant them a little bit earlier in the year than more sensitive plants.

The earliest that you can plant tall phlox in Sierra Vista 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 tall phlox and expect a good harvest is probably September. If you wait any later than that and your tall phlox may not have a chance to fully mature. You can get started a little bit earlier by starting your tall phlox indoors.

Last Frost Date

On average the last frost has passed is on March 15 in Sierra Vista. You can expect an average low temperature of 15°F in the coldest months of winter.

Keep in mind that USDA zone info for Sierra Vista is an average and the actual date of last frost is different every year. Half of the time in Sierra Vista you get surprised by a frost after March 15 so always be ready to cover your tall phlox 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.