One of the first steps you take when you are getting a good idea your gardening schedule is find your 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.

You can figure out when to plant pennyroyal in Hilton Head Island by using the USDA zone info.

Planting Calendar for Pennyroyal

Frost tolerance for pennyroyal:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since pennyroyal are very cold tolerant you can plant them earlier in the year than other frost tender plants.

The earliest that you can plant pennyroyal in Hilton Head Island 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 pennyroyal and expect a good harvest is probably September. Any later than that and your pennyroyal may not have a chance to really do well. Starting your pennyroyal indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is March 15 in Hilton Head Island. It might get as low as 15°F during the coldest months of winter.

Since the USDA zone info for Hilton Head Island is not always accurate the actual date of last frost will vary from year to year. Since half of the time in Hilton Head Island you get surprised by a frost after March 15 be ready to cover your pennyroyal in the event of a surprise 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.