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 common way of determining when it's the best time to plant phlox is to refer to the USDA zone info for Zion.

Planting Calendar for Phlox

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

Phlox can survive in moderate cold which tells us that you can plant them just a bit earlier in the year than more sensitive plants.

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

Last Frost Date

On average all chance of frost has passed is on April 15 in Zion. It might get as low as -15°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Zion is not always accurate and the actual date of last frost will vary from year to year. Half of the time in Zion there is a last frost after April 15 so always be ready to cover your phlox in the event of a surprise late frost.

USDA Zone Info for Zion

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°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 -10°F.

Plants to Grow in Zion

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