One of the first steps you take when you are determining 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.

You can determine when it's the best time to plant cosmos in South Haven 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 ok in moderate cold which means that you can get them planted just a bit earlier than plants that are more sensitive to the cold.

The earliest that you can plant cosmos in South Haven 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. Starting your cosmos indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on April 15 in South Haven. It might get as low as -5°F during the coldest months of winter.

Always keep in mind that USDA zone info for South Haven is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in South Haven it frosts late in the year after April 15 so make sure that you are prepared to cover your cosmos in the event of a surprise late frost.

USDA Zone Info for South Haven

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 South Haven

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