Before planting it is a good idea to find your USDA Zone info to determine your garden 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 gladiolus in Philadelphia should be estimated by using the USDA zone info.

Planting Calendar for Gladiolus

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

You can plant gladiolus a bit earlier in the year because they are one of those plants that can tolerate a tiny bit of cold weather.

The earliest that you can plant gladiolus 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 gladiolus and expect a good harvest is probably August. Any later than that and your gladiolus may not have a chance to really do well. You can get started a few weeks earlier by starting your gladiolus indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Philadelphia. It might get as low as 0°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Philadelphia is an average and 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 make sure that you are prepared to cover your gladiolus if you have 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 Low	0°F
Highest Expected Low	5°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.