Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The best time to plant dahlia in Columbia Falls can be determined by looking at the USDA zone info.

Planting Calendar for Dahlia

Frost tolerance for dahlia:	Not tolerant of frost.
When to plant:	After the last frost has passed.

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

The earliest that you can plant dahlia 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 dahlia and expect a good harvest is probably August. Any later than that and your dahlia may not have a chance to really do well. Starting your dahlia indoors is a great way to get them started a couple of weeks earlier.

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.

Just be sure to remember that USDA zone info for Columbia Falls is an average and the actual date of last frost will vary from year to year. Half of the time in Columbia Falls it frosts late in the year after April 15 so always be ready to protect your dahlia in the event of 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.