One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By referring to the USDA zone info for Siloam Springs you should be able to figure out when you can plant pennyroyal.

Planting Calendar for Pennyroyal

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

You can plant pennyroyal earlier in the year because they do well in cold.

The earliest that you can plant pennyroyal in Siloam Springs 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. You probably don't want to wait any later than that or else 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 couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Siloam Springs. You can expect an average low temperature of 0°F in the coldest months of winter.

Always keep in mind that USDA zone info for Siloam Springs is not always accurate and the actual date of last frost is different every year. Half of the time in Siloam Springs you get surprised by a frost after April 15 so just be sure to be ready to cover your pennyroyal if you have one of those late frosts.

USDA Zone Info for Siloam Springs

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 Siloam Springs

You may be interested in your other planting guides for Siloam Springs.