One of the best tools that you have as gardeners to help us figure out 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.

In Cedar Rapids you can estimate when it's a good idea to plant cosmos 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.

Cosmos do well in mild cold which tells us that 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 Cedar Rapids 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 fully mature. You can get started a little bit earlier by starting your cosmos indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Cedar Rapids. It might get as low as -20°F during the coldest months of winter.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Cedar Rapids and it can change quite a bit from year to year. Half of the time in Cedar Rapids it frosts late in the year after April 15 so just be sure to be ready to protect your cosmos if you have one of those late frosts.

USDA Zone Info for Cedar Rapids

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°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 -15°F.

Plants to Grow in Cedar Rapids

You may be interested in your other planting guides for Cedar Rapids.