One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Columbia Falls should be reviewed to estimate when it's a good idea to plant oxalis.

Planting Calendar for Oxalis

Frost tolerance for oxalis:	Not tolerant of frost.
When to plant:	After the last frost.

You can not plant oxalis until after all chance of frost has passed because they require warm weather.

The earliest that you can plant oxalis 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 oxalis and expect a good harvest is probably August. Any later than that and your oxalis may not have a chance to fully mature. If you are starting your oxalis indoors then you might be able to get away with starting them a few 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.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Columbia Falls and it is different every year. Half of the time in Columbia Falls you get surprised by a frost after April 15 so be sure to be ready to cover your oxalis 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.