When to Plant Phlox in Shenandoah, IA

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.

By looking at the USDA zone info for Shenandoah it's a good idea to determine when it's a good idea to plant phlox.


Planting Calendar for Phlox

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

Phlox do well in mild cold which tells us that 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 Shenandoah 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 fully mature. If you are starting your phlox indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Shenandoah the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Shenandoah and it will vary from year to year. Since half of the time in Shenandoah you get a frost after April 15 be ready to protect your phlox if you have one of those late frosts.

USDA Zone Info for Shenandoah

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-15°F
Highest Expected Low-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Shenandoah

You may be interested in your other planting guides for Shenandoah.