When to Plant Flower-of-an-Hour in Philadelphia, PA

Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's a good idea to figure out when it's possible to plant flower-of-an-hour by reviewing the USDA zone info for Philadelphia.


Planting Calendar for Flower-of-an-Hour

Frost tolerance for flower-of-an-hour: Tolerant of a very small amount of frost.
When to plant: Up to 3 weeks before last frost.

Flower-of-an-Hour do ok in moderate cold which means that you can plant them slightly earlier than other frost tender plants.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant flower-of-an-hour
Possibly ok, but a risky time to plant flower-of-an-hour
Probably not a good time to plant flower-of-an-hour

The earliest that you can plant flower-of-an-hour in Philadelphia 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 flower-of-an-hour and expect a good harvest is probably August. Any later than that and your flower-of-an-hour may not have a chance to really do well. If you are starting your flower-of-an-hour indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Philadelphia is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Philadelphia you get surprised by a frost after April 15 so just be sure to be ready to protect your flower-of-an-hour in the event of one of those late frosts.

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.