Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant pennyroyal in Hermiston can be estimated by referring to 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 tend to make it in quite a bit of cold which tells us that you can plant them earlier in the year than other plants that might not handle the cold.

The earliest that you can plant pennyroyal in Hermiston 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. If you wait any later than that and your pennyroyal may not have a chance to really do well. If you are starting your pennyroyal indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Hermiston. It might get as low as 0°F during the coldest months of winter.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Hermiston and it changes from year to year. Half of the time in Hermiston last frost occurs after April 15 so just be sure to be ready to cover your pennyroyal in the event of one of those late frosts.

USDA Zone Info for Hermiston

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Hermiston

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