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 looking at the USDA zone info for Cottage Grove you will be able to determine 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.

Since pennyroyal are very cold tolerant you can plant them quite a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant pennyroyal in Cottage Grove 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. 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 is on May 15 in Cottage Grove. You can expect an average low temperature of -25°F in 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 Cottage Grove and it will vary from year to year. Half of the time in Cottage Grove you get surprised by a frost after May 15 so just be sure to be ready to protect your pennyroyal if you have a surprise late frost.

USDA Zone Info for Cottage Grove

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 Cottage Grove

You may be interested in your other planting guides for Cottage Grove.