Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Lock Haven can be used to estimate when it's the best time to plant cosmos.

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 tells us that you can plant them slightly earlier than more sensitive plants.

The earliest that you can plant cosmos in Lock Haven 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 really do well. If you are starting your cosmos indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

Just be sure to remember that USDA zone info for Lock Haven may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Lock Haven you get a frost after April 15 so make sure that you are prepared to protect your cosmos if you have a late frost.

USDA Zone Info for Lock Haven

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 Lock Haven

You may be interested in your other planting guides for Lock Haven.