When to Plant Tall Phlox in Columbia Falls, MT

One of the first steps you take when you are determining 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.

You can figure out when it's a good idea to plant tall phlox in Columbia Falls by checking out the USDA zone info.


Planting Calendar for Tall Phlox

Frost tolerance for tall phlox: Tolerant of some frost.
When to plant: Up to 5 weeks before last frost.

Tall Phlox do well in moderate cold which means that you can plant them earlier than more sensitive plants.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant tall phlox
Possibly ok, but a risky time to plant tall phlox
Probably not a good time to plant tall phlox

The earliest that you can plant tall phlox 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 tall phlox and expect a good harvest is probably September. If you wait any later than that and your tall phlox may not have a chance to grow to maturity. You can get started a little bit earlier by starting your tall phlox indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Columbia Falls. You can expect an average low temperature of -20°F in the coldest months of winter.

Since the USDA zone info for Columbia Falls may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Columbia Falls you get a frost after April 15 so be sure to be ready to protect your tall phlox 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.