When to Plant Pennyroyal in Zone 1a

Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The best time to plant pennyroyal in Zone 1a can be determined by looking at 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 quite a bit earlier in the year than more sensitive plants.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant pennyroyal
Possibly ok, but a risky time to plant pennyroyal
Probably not a good time to plant pennyroyal

The earliest that you can plant pennyroyal in Zone 1a is May. However, you really should wait until June if you don't want to take any chances.

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

Last Frost Date

On average the last frost has passed is on June 15 in Zone 1a. You can expect an average low temperature of -60°F in the coldest months of winter.

Since the USDA zone info for Zone 1a is not always accurate the actual date of last frost changes from year to year. Half of the time in Zone 1a last frost occurs after June 15 so make sure that you are ready to protect your pennyroyal if you have a late frost.

USDA Zone Info for Zone 1a

Here is the info for USDA Zone 1a.

Average Date of Last Frost (spring)June 15
Average Date of First Frost (fall)July 15
Lowest Expected Low-60°F
Highest Expected Low-55°F

This means that on a really cold year, the coldest it will get is -60°F. On most years you should be prepared to experience lows near -55°F.

Plants to Grow in Zone 1a

You may be interested in your other planting guides for Zone 1a.