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.

The earliest that you can plant cosmos in Lake Forest can 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.

Since cosmos do ok in moderate cold you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant cosmos in Lake Forest 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. Any later than that and your cosmos may not have a chance to fully mature. If you are starting your cosmos indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is January 31 in Lake Forest. You can expect an average low temperature of 30°F in the coldest months of winter.

It's important to remember that USDA zone info for Lake Forest is not always accurate and the actual date of last frost is different every year. Half of the time in Lake Forest you get surprised by a frost after January 31 so be sure to be ready to cover your cosmos in the event of a surprise late frost.

USDA Zone Info for Lake Forest

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Lake Forest

You may be interested in your other planting guides for Lake Forest.