Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Harrisonburg can be read 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.

Tall Phlox tend to make it in some cold which tells us that you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant tall phlox in Harrisonburg 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 grow to maturity. If you are starting your tall phlox indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Harrisonburg. It might get as low as -5°F during the coldest months of winter.

Remember that USDA zone info for Harrisonburg may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Harrisonburg you get surprised by a frost after April 15 so be sure to be ready to protect your tall phlox in the event of one of those late frosts.

USDA Zone Info for Harrisonburg

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°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 0°F.

Plants to Grow in Harrisonburg

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