The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of determining when it's the best time to plant rosemary is to look at the USDA zone info for Miles City.

Planting Calendar for Rosemary

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

Rosemary tend to make it in a bit of cold which tells us that you can plant them a lot earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant rosemary in Miles City 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 rosemary and expect a good harvest is probably August. Any later than that and your rosemary may not have a chance to grow to maturity. Starting your rosemary indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on May 15 in Miles City. In the coldest months of winter you can expect an average low temperature of -30°F.

Always keep in mind that USDA zone info for Miles City is an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Miles City you get a frost after May 15 be ready to cover your rosemary in the event of a surprise late frost.

USDA Zone Info for Miles City

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Miles City

You may be interested in your other planting guides for Miles City.