The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Bartlesville you can estimate when you can plant cosmos by checking out 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.

Since cosmos do ok in moderate cold you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant cosmos in Bartlesville 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. You probably don't want to wait any later than that or else your cosmos may not have a chance to grow to maturity. If you are starting your cosmos indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Bartlesville and it will vary from year to year. Half of the time in Bartlesville you get surprised by a frost after April 15 so be sure to be ready to cover your cosmos if you have a surprise late frost.

USDA Zone Info for Bartlesville

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 Bartlesville

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