One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By checking out the USDA zone info for Coralville it's possible to figure out when it's a good idea to plant tall phlox.

Planting Calendar for Tall Phlox

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

You can plant tall phlox a little earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant tall phlox in Coralville 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. Starting your tall phlox indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Coralville and it will vary from year to year. Since half of the time in Coralville there is a last frost after April 15 be ready to cover your tall phlox if you have a late frost.

USDA Zone Info for Coralville

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 Coralville

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