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.

In Prospect you can determine when you can 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 very little cold which means that you can plant them slightly earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant cosmos in Prospect 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. You probably don't want to wait any later than that or else your cosmos may not have a chance to fully mature. 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 when the weather gets warmer is on April 15 in Prospect. You should expect an average low temperature of -5°F in the coldest months of winter.

Keep in mind that USDA zone info for Prospect is not always accurate and the actual date of last frost changes from year to year. Since half of the time in Prospect last frost occurs after April 15 be ready to cover your cosmos in the event of a surprise late frost.

USDA Zone Info for Prospect

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 Prospect

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