One of the first steps you take when you are estimating your gardening schedule is find your 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.

A way of estimating when you can plant iresene is to refer to the USDA zone info for Pittsburgh.

Planting Calendar for Iresene

Frost tolerance for iresene:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Iresene do not do well in cold weather which tells us that you have to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant iresene in Pittsburgh is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant iresene and expect a good harvest is probably August. If you wait any later than that and your iresene may not have a chance to really do well. Starting your iresene indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Pittsburgh the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -5°F.

Since the USDA zone info for Pittsburgh is just an average the actual date of last frost will vary from year to year. Since half of the time in Pittsburgh there is a last frost after April 15 be ready to cover your iresene in the event of 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.