Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can determine when to plant cosmos in La Crosse by using 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 slightly earlier in the year than other plants that might not handle the cold.

The earliest that you can plant cosmos in La Crosse is April. However, you really should wait until May 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. 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 May 15 in La Crosse. It might get as low as -25°F during the coldest months of winter.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for La Crosse and it is different every year. Since half of the time in La Crosse you get surprised by a frost after May 15 be ready to cover your cosmos if you have one of those late frosts.

USDA Zone Info for La Crosse

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

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

Plants to Grow in La Crosse

You may be interested in your other planting guides for La Crosse.