One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

One way of determining when to plant zinnia is to consult the USDA zone info for Glassport.

Planting Calendar for Zinnia

Frost tolerance for zinnia:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since zinnia do not do well in cold weather it's important to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant zinnia in Glassport 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 zinnia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your zinnia may not have a chance to grow to maturity. If you are starting your zinnia indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Glassport. In the coldest months of winter you can expect an average low temperature of -5°F.

Since the USDA zone info for Glassport is just an average the actual date of last frost is different every year. Half of the time in Glassport it frosts late in the year after April 15 so make sure that you are ready to protect your zinnia in the event of a late frost.

USDA Zone Info for Glassport

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 Glassport

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