When to Plant Tall Phlox in Zone 3a

Before planting it is a good idea to find your USDA Zone info to estimate 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.

In Zone 3a you can estimate when it's a good idea to plant tall phlox by looking at 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.

You can plant tall phlox a little bit earlier in the year because they are moderately cold tolerant.

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 Zone 3a is March. However, you really should wait until April 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 August. 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 few weeks earlier by starting your tall phlox indoors.

Last Frost Date

The average date of last frost is May 15 in Zone 3a. In the coldest months of winter you should expect an average low temperature of -40°F.

Keep in mind that USDA zone info for Zone 3a is just an average and the actual date of last frost will vary from year to year. Half of the time in Zone 3a last frost occurs after May 15 so make sure that you are prepared to protect your tall phlox in the event of a late frost.

USDA Zone Info for Zone 3a

Here is the info for USDA Zone 3a.

Average Date of Last Frost (spring)May 15
Average Date of First Frost (fall)September 15
Lowest Expected Low-40°F
Highest Expected Low-35°F

This means that on a really cold year, the coldest it will get is -40°F. On most years you should be prepared to experience lows near -35°F.

Plants to Grow in Zone 3a

You may be interested in your other planting guides for Zone 3a.