One of the first steps you take when you are estimating your gardening schedule is find your 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.

The first chance to plant cosmos in South Holland should be determined by checking out 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.

You can plant cosmos a bit earlier in the year because they do ok in moderate cold.

The earliest that you can plant cosmos in South Holland 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 grow to maturity. You can get started a couple of weeks earlier by starting your cosmos indoors.

Last Frost Date

The average date of last frost is April 15 in South Holland. It might get as low as -10°F during the coldest months of winter.

Always keep in mind that USDA zone info for South Holland is just an average and the actual date of last frost will vary from year to year. Half of the time in South Holland it frosts late in the year after April 15 so always be ready to cover your cosmos if you have a surprise late frost.

USDA Zone Info for South Holland

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in South Holland

You may be interested in your other planting guides for South Holland.