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.

It's a good idea to estimate when it's a good idea to plant tall phlox by looking at the USDA zone info for Irmo.

Planting Calendar for Tall Phlox

Frost tolerance for tall phlox:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since tall phlox are one of those plants that can tolerate a little bit of cold weather you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant tall phlox in Irmo 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. You can get started a little bit earlier by starting your tall phlox indoors.

Last Frost Date

On average all chance of frost has passed is on March 15 in Irmo. You can expect an average low temperature of 10°F in the coldest months of winter.

Since the USDA zone info for Irmo is just an average the actual date of last frost is different every year. Since half of the time in Irmo last frost occurs after March 15 be ready to cover your tall phlox in the event of a surprise late frost.

USDA Zone Info for Irmo

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Irmo

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