One of the first steps you take when you are figuring out 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.

You can determine when it's possible to plant tall phlox in Winthrop Harbor 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.

Tall Phlox are one of those plants that can tolerate a little bit of cold weather which tells us that you can start planting them earlier than other plants that might not handle the cold.

The earliest that you can plant tall phlox in Winthrop Harbor 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 fully mature. You can get started a few weeks earlier by starting your tall phlox indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Winthrop Harbor. In the coldest months of winter you should expect an average low temperature of -15°F.

It's important to remember that USDA zone info for Winthrop Harbor is an average and the actual date of last frost is different every year. Since half of the time in Winthrop Harbor it frosts late in the year after April 15 be ready to protect your tall phlox in the event of a late frost.

USDA Zone Info for Winthrop Harbor

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 Winthrop Harbor

You may be interested in your other planting guides for Winthrop Harbor.