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.

In Bothell you can figure out when it's a good idea to plant cosmos 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.

You can plant cosmos just a tiny bit earlier in the year because they do ok in moderate cold.

The earliest that you can plant cosmos in Bothell 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. Starting your cosmos indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Bothell the average date of last frost happens on March 15. In the coldest months of winter you should expect an average low temperature of 15°F.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Bothell and it can change quite a bit from year to year. Half of the time in Bothell you get surprised by a frost after March 15 so just be sure to be ready to protect your cosmos in the event of a surprise late frost.

USDA Zone Info for Bothell

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 Bothell

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