One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to estimate when it's the best time to plant spinach by referring to the USDA zone info for Philadelphia.

Planting Calendar for Spinach

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

Spinach do ok in mild cold which tells us that you can plant them just a bit earlier in the year than more sensitive plants.

The earliest that you can plant spinach 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 spinach and expect a good harvest is probably September. You probably don't want to wait any later than that or else your spinach may not have a chance to grow to maturity. Starting your spinach indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Philadelphia the average date of last frost happens on March 15. You should expect an average low temperature of 10°F in the coldest months of winter.

It's important to remember that USDA zone info for Philadelphia may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in Philadelphia last frost occurs after March 15 be ready to protect your spinach if you have a late frost.

USDA Zone Info for Philadelphia

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

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

Plants to Grow in Philadelphia

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