When to Plant Cosmos in Manheim, PA

One of the first steps you take when you are figuring out 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 should be able to determine when it's possible to plant cosmos by looking at the USDA zone info for Manheim.


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.

You can plant cosmos slightly earlier in the year because they are barely cold tolerant.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant cosmos
Possibly ok, but a risky time to plant cosmos
Probably not a good time to plant cosmos

The earliest that you can plant cosmos in Manheim 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. If you wait any later than that and your cosmos may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your cosmos indoors.

Last Frost Date

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

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Manheim and it will vary from year to year. Half of the time in Manheim last frost occurs after April 15 so be sure to be ready to cover your cosmos in the event of a surprise late frost.

USDA Zone Info for Manheim

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 Low0°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 Manheim

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