One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By using the USDA zone info for Hilton Head Island you will be able to figure out when it's the best time to plant dahlia.

Planting Calendar for Dahlia

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

Since dahlia are not cold tolerant it is important to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant dahlia in Hilton Head Island 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 dahlia and expect a good harvest is probably August. If you wait any later than that and your dahlia may not have a chance to really do well. Starting your dahlia indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Hilton Head Island the average date of last frost happens on March 15. It might get as low as 15°F during the coldest months of winter.

Since the USDA zone info for Hilton Head Island is an average the actual date of last frost is different every year. Since half of the time in Hilton Head Island you get a frost after March 15 be ready to protect your dahlia if you have a late frost.

USDA Zone Info for Hilton Head Island

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Hilton Head Island

You may be interested in your other planting guides for Hilton Head Island.