One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of estimating when to plant cosmos is to check out the USDA zone info for South Lake Tahoe.

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 tells us that you can start planting them slightly earlier than other plants that might not handle the cold.

The earliest that you can plant cosmos in South Lake Tahoe 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. If you are starting your cosmos indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in South Lake Tahoe. You can expect an average low temperature of -5°F in the coldest months of winter.

Since the USDA zone info for South Lake Tahoe may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in South Lake Tahoe there is a last frost after April 15 be ready to protect your cosmos if you have one of those late frosts.

USDA Zone Info for South Lake Tahoe

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 Lake Tahoe

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