The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By looking at the USDA zone info for Denison it's possible to estimate when 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 do ok in very little cold which means that you can plant them slightly earlier in the year than other plants that might not handle the cold.

The earliest that you can plant cosmos in Denison 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 grow to maturity. Starting your cosmos indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost is on March 15 in Denison. In the coldest months of winter you can expect an average low temperature of 10°F.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Denison and it can change quite a bit from year to year. Half of the time in Denison it frosts late in the year after March 15 so always be ready to protect your cosmos in the event of a surprise late frost.

USDA Zone Info for Denison

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Denison

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