Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant cosmos in Phoenixville should be figured out by looking at the USDA zone info.

Planting Calendar for Cosmos

Frost tolerance for cosmos:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Cosmos are barely cold tolerant which means that you can get them planted just a bit earlier than other frost tender plants.

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

The last month that you can plant cosmos and expect a good harvest is probably August. Any later than that and your cosmos may not have a chance to fully mature. If you are starting your cosmos indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Phoenixville the average date of last frost happens on April 15. It might get as low as -5°F during the coldest months of winter.

Since the USDA zone info for Phoenixville is not always accurate the actual date of last frost is different every year. Half of the time in Phoenixville you get surprised by a frost after April 15 so make sure that you are ready to protect your cosmos in the event of a late frost.

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.