The USDA Zone info is a great tool for gardeners to help us estimate 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.

A way of estimating when it's a good idea to plant heliotrope is to consult the USDA zone info for Columbia Falls.

Planting Calendar for Heliotrope

Frost tolerance for heliotrope:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

It's not a good idea to plant heliotrope until after the last frost because they do not do well in cold weather.

The earliest that you can plant heliotrope in Columbia Falls is April. However, you really should wait until May if you don't want to take any chances.

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

Last Frost Date

In Columbia Falls the average date of last frost happens on April 15. It might get as low as -20°F during the coldest months of winter.

Since the USDA zone info for Columbia Falls is an average the actual date of last frost changes from year to year. Since half of the time in Columbia Falls last frost occurs after April 15 be ready to protect your heliotrope if you have a surprise 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.