One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Round Lake you can determine when to plant tall phlox by referring to 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 are moderately cold tolerant which tells us that you can plant them a little bit earlier than other plants that might not handle the cold.

The earliest that you can plant tall phlox in Round Lake 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. Any later than that and your tall phlox may not have a chance to really do well. Starting your tall phlox indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Round Lake. You should expect an average low temperature of -15°F in the coldest months of winter.

It's important to remember that USDA zone info for Round Lake is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Round Lake you get a frost after April 15 so make sure that you are prepared to protect your tall phlox if you have a late frost.

USDA Zone Info for Round Lake

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 Round Lake

You may be interested in your other planting guides for Round Lake.