Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The best time to plant tall phlox in Umatilla should be determined by checking out 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.

Since tall phlox are one of those plants that can tolerate a little bit of cold weather you can plant them just a bit earlier in the year than more sensitive plants.

The earliest that you can plant tall phlox in Umatilla 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. You probably don't want to wait any later than that or else your tall phlox may not have a chance to fully mature. Starting your tall phlox indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Umatilla the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of 5°F.

Always keep in mind that USDA zone info for Umatilla is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Umatilla it frosts late in the year after April 15 so just be sure to be ready to cover your tall phlox in the event of one of those late frosts.

USDA Zone Info for Umatilla

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Umatilla

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