When to Plant Phlox in Allentown, PA

The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant phlox in Allentown can be figured out 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.

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

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 Allentown 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. You can get started a little bit earlier by starting your phlox indoors.

Last Frost Date

The average date of last frost is April 15 in Allentown. It might get as low as -5°F during the coldest months of winter.

Keep in mind that USDA zone info for Allentown is an average and the actual date of last frost is different every year. Half of the time in Allentown there is a last frost after April 15 so make sure that you are ready to protect your phlox if you have a surprise late frost.

USDA Zone Info for Allentown

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-5°F
Highest Expected Low0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Allentown

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