The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. 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 estimating when it's a good idea to plant heuchera is to examine the USDA zone info for Irmo.

Planting Calendar for Heuchera

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

You can plant heuchera a bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant heuchera 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 heuchera and expect a good harvest is probably September. If you wait any later than that and your heuchera may not have a chance to fully mature. If you are starting your heuchera indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Irmo. You can expect an average low temperature of 10°F in the coldest months of winter.

Keep in mind that USDA zone info for Irmo is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Irmo last frost occurs after March 15 so just be sure to be ready to protect your heuchera 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.