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.

One way of making a decision about when it's a good idea to plant tall phlox is to refer to the USDA zone info for Marathon.

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 are moderately cold tolerant which tells us that you can plant them a little bit earlier than plants that are more sensitive to the cold.

The earliest that you can plant tall phlox in Marathon is January. However, you really should wait until February 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 November. Any later than that and your tall phlox may not have a chance to fully mature. If you are starting your tall phlox indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Marathon it never frosts. You should expect an average low temperature of 45°F in the coldest months of winter.

Since the USDA zone info for Marathon is not always accurate the actual date of last frost will vary from year to year. Since it never frosts in Marathon you do not have to be ready to protect your tall phlox in the event of a late frost.

USDA Zone Info for Marathon

Here is the info for USDA Zone 11b.

Average Date of Last Frost (spring)	Never
Average Date of First Frost (fall)	Never
Lowest Expected Low	45°F
Highest Expected Low	50°F

This means that on a really cold year, the coldest it will get is 45°F. On most years you should be prepared to experience lows near 50°F.

Plants to Grow in Marathon

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