The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first chance to plant cosmos in Kelso can be estimated by looking at 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 can survive in some cold which means that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant cosmos in Kelso 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 really do well. You can get started a little bit earlier by starting your cosmos indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Kelso. In the coldest months of winter you can expect an average low temperature of 15°F.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Kelso and it will vary from year to year. Half of the time in Kelso last frost occurs after March 15 so make sure that you are prepared to protect your cosmos in the event of one of those late frosts.

USDA Zone Info for Kelso

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Kelso

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