The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first chance to plant rosemary in Columbia Falls can be determined by looking at the USDA zone info.

Planting Calendar for Rosemary

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

Rosemary are very cold tolerant which tells us that you can plant them a quite a bit earlier than more sensitive plants.

The earliest that you can plant rosemary in Columbia Falls 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 rosemary and expect a good harvest is probably September. If you wait any later than that and your rosemary may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your rosemary indoors.

Last Frost Date

In Columbia Falls the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -20°F.

Remember that USDA zone info for Columbia Falls is just an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Columbia Falls you get a frost after April 15 be ready to protect your rosemary if you have a late frost.

USDA Zone Info for Columbia Falls

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Columbia Falls

You may be interested in your other planting guides for Columbia Falls.