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.

A way of estimating when it's the best time to plant hardy hibiscus is to check out the USDA zone info for Miles City.

Planting Calendar for Hardy Hibiscus

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

Since hardy hibiscus do well in cold you can plant them a lot earlier in the year than other plants that might not handle the cold.

The earliest that you can plant hardy hibiscus 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 hardy hibiscus and expect a good harvest is probably August. You probably don't want to wait any later than that or else your hardy hibiscus may not have a chance to really do well. You can get started a couple of weeks earlier by starting your hardy hibiscus indoors.

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.

It's important to remember that USDA zone info for Miles City may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Since half of the time in Miles City there is a last frost after May 15 be ready to cover your hardy hibiscus if you have one of those late frosts.

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.