One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when it's a good idea to plant zinnia in Phoenixville by checking out the USDA zone info.

Planting Calendar for Zinnia

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

Since zinnia are not cold tolerant you need to wait until after the last frost has passed before you can plant them.

The earliest that you can plant zinnia in Phoenixville 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 fully mature. If you are starting your zinnia indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Remember that USDA zone info for Phoenixville is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Phoenixville it frosts late in the year after April 15 so always be ready to protect your zinnia if you have one of those late frosts.

USDA Zone Info for Phoenixville

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 Phoenixville

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