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.

A common way of getting a good idea when it's possible to plant cosmos is to check out the USDA zone info for Valley.

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 tend to make it in a tiny bit of cold which means that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant cosmos in Valley 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 grow to maturity. You can get started a few weeks earlier by starting your cosmos indoors.

Last Frost Date

In Valley the average date of last frost happens on March 15. It might get as low as 10°F during the coldest months of winter.

Since the USDA zone info for Valley is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Valley it frosts late in the year after March 15 so make sure that you are prepared to cover your cosmos if you have a late frost.

USDA Zone Info for Valley

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Valley

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