When to Plant Phlox in Mason City, IA

One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first opportunity to plant phlox in Mason City should be determined by reviewing the USDA zone info.


Planting Calendar for Phlox

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

Since phlox do well in moderate cold you can plant them a little bit earlier in the year than other plants that might not handle the cold.

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

The earliest that you can plant phlox in Mason City 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 phlox and expect a good harvest is probably September. You probably don't want to wait any later than that or else your phlox may not have a chance to grow to maturity. Starting your phlox indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Mason City. In the coldest months of winter you should expect an average low temperature of -20°F.

Since the USDA zone info for Mason City may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Mason City last frost occurs after April 15 so make sure that you are ready to cover your phlox in the event of one of those late frosts.

USDA Zone Info for Mason City

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 Mason City

You may be interested in your other planting guides for Mason City.