The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Pittsburgh can be used to estimate when you can plant helianthemum.

Planting Calendar for Helianthemum

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

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

The earliest that you can plant helianthemum 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 helianthemum and expect a good harvest is probably September. Any later than that and your helianthemum may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your helianthemum indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Pittsburgh. In the coldest months of winter you can expect an average low temperature of -5°F.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Pittsburgh and it will vary from year to year. Since half of the time in Pittsburgh you get a frost after April 15 be ready to cover your helianthemum if you have a late frost.

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.