The USDA Zone info is a great tool for gardeners to help us figure out 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.

The USDA zone info for Irmo should be reviewed to figure out when it's a good idea to plant dahlias.

Planting Calendar for Dahlias

Frost tolerance for dahlias:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since dahlias are not cold tolerant it's necessary to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant dahlias in Irmo is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant dahlias and expect a good harvest is probably August. You probably don't want to wait any later than that or else your dahlias may not have a chance to grow to maturity. You can get started a little bit earlier by starting your dahlias indoors.

Last Frost Date

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

Keep in mind that USDA zone info for Irmo is not always accurate and the actual date of last frost will vary from year to year. Half of the time in Irmo you get surprised by a frost after March 15 so make sure that you are ready to protect your dahlias if you have a 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.