One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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 Cottage Grove you can determine when it's possible to plant cosmos by reviewing 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 are barely cold tolerant you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant cosmos in Cottage Grove 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 fully mature. 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 Cottage Grove the average date of last frost happens on May 15. You can expect an average low temperature of -25°F in the coldest months of winter.

It's important to remember that USDA zone info for Cottage Grove may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Cottage Grove you get surprised by a frost after May 15 so just be sure to be ready to cover your cosmos if you have one of those late frosts.

USDA Zone Info for Cottage Grove

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 Cottage Grove

You may be interested in your other planting guides for Cottage Grove.