One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

A way of making a decision about when you can plant tall phlox is to look at the USDA zone info for Baltimore.

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 start planting them earlier than other plants that might not handle the cold.

The earliest that you can plant tall phlox in Baltimore 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 grow to maturity. You can get started a couple of weeks earlier by starting your tall phlox indoors.

Last Frost Date

In Baltimore the average date of last frost happens on April 15. It might get as low as 5°F during the coldest months of winter.

Since the USDA zone info for Baltimore is just an average the actual date of last frost changes from year to year. Half of the time in Baltimore you get a frost after April 15 so make sure that you are ready to cover your tall phlox if you have a late frost.

USDA Zone Info for Baltimore

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 Baltimore

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