One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Buckeye you can estimate when it's the best time to plant cosmos by referring to 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.

You can plant cosmos just a tiny bit earlier in the year because they are barely cold tolerant.

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

The last month that you can plant cosmos and expect a good harvest is probably September. 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 little bit earlier.

Last Frost Date

The average date of last frost is February 15 in Buckeye. In the coldest months of winter you should expect an average low temperature of 20°F.

Since the USDA zone info for Buckeye may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Buckeye it frosts late in the year after February 15 be ready to cover your cosmos in the event of one of those late frosts.

USDA Zone Info for Buckeye

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Buckeye

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