One of the first steps you take when you are estimating 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.

By using the USDA zone info for Ashland you will be able to figure out when it's a good idea to plant pennyroyal.

Planting Calendar for Pennyroyal

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

Pennyroyal do well in a bit of cold which tells us that you can plant them earlier in the year than other frost tender plants.

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

The last month that you can plant pennyroyal and expect a good harvest is probably August. Any later than that and your pennyroyal may not have a chance to grow to maturity. Starting your pennyroyal indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on May 15 in Ashland. You can expect an average low temperature of -25°F in the coldest months of winter.

Keep in mind that USDA zone info for Ashland 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 Ashland there is a last frost after May 15 so make sure that you are ready to cover your pennyroyal in the event of a late frost.

USDA Zone Info for Ashland

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Ashland

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