One of the first steps you take when you are figuring out 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.

In Vail you can estimate when to plant pennyroyal 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.

Pennyroyal do well in cold which means that you can plant them a quite a bit earlier than plants that are more sensitive to the cold.

The earliest that you can plant pennyroyal in Vail 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 fully mature. If you are starting your pennyroyal indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Vail the average date of last frost happens on May 15. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Vail may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Vail it frosts late in the year after May 15 so always be ready to protect your pennyroyal in the event of one of those late frosts.

USDA Zone Info for Vail

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 Vail

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