One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Huron can be read to determine 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.

Since cosmos do ok in moderate cold you can plant them just a tiny bit earlier in the year than other frost tender plants.

The earliest that you can plant cosmos in Huron 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. Any later than that and your cosmos may not have a chance to fully mature. 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 Huron the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -5°F.

Always 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 Huron and it changes from year to year. Half of the time in Huron it frosts late in the year after April 15 so make sure that you are prepared to protect your cosmos in the event of one of those late frosts.

USDA Zone Info for Huron

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 Huron

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