Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You will be able to estimate when you can plant cosmos by checking out the USDA zone info for Exeter.

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 mild cold which means that you can plant them slightly earlier in the year than more sensitive plants.

The earliest that you can plant cosmos in Exeter is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant cosmos and expect a good harvest is probably September. If you wait any later than that and your cosmos may not have a chance to grow to maturity. If you are starting your cosmos indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Exeter the average date of last frost happens on February 15. You can expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Exeter is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Exeter you get surprised by a frost after February 15 be ready to protect your cosmos if you have a surprise late frost.

USDA Zone Info for Exeter

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°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 30°F.

Plants to Grow in Exeter

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