The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The best time to plant sweet williams in Pittsburgh can be figured out by looking at the USDA zone info.

Planting Calendar for Sweet Williams

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

Sweet Williams are one of those plants that can tolerate a little bit of cold weather which tells us that you can start planting them earlier than more sensitive plants.

The earliest that you can plant sweet williams in Pittsburgh 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 sweet williams and expect a good harvest is probably September. Any later than that and your sweet williams may not have a chance to fully mature. You can get started a few weeks earlier by starting your sweet williams indoors.

Last Frost Date

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

Just be sure to remember that USDA zone info for Pittsburgh may not be accurate from year to year and the actual date of last frost will vary from year to year. Since half of the time in Pittsburgh it frosts late in the year after April 15 be ready to protect your sweet williams if you have one of those late frosts.

USDA Zone Info for Pittsburgh

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 Low	0°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 Pittsburgh

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