When to Plant Radishes in Philadelphia, PA

One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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 earliest that you can plant radishes in Philadelphia should be estimated by reviewing the USDA zone info.


Planting Calendar for Radishes

Frost tolerance for radishes: Very tolerant of frost.
When to plant: Up to 7 weeks before last frost.

Radishes are one of those plants that can tolerate quite a bit of cold weather which means that you can plant them a quite a bit earlier than other plants that might not handle the cold.

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

The earliest that you can plant radishes in Philadelphia 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 radishes and expect a good harvest is probably September. Any later than that and your radishes may not have a chance to fully mature. If you are starting your radishes indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Philadelphia the average date of last frost happens on April 15. You can expect an average low temperature of 0°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Philadelphia is just an average and the actual date of last frost changes from year to year. Since half of the time in Philadelphia it frosts late in the year after April 15 be ready to protect your radishes in the event of a late frost.

USDA Zone Info for Philadelphia

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low0°F
Highest Expected Low5°F

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

Plants to Grow in Philadelphia

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