Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's a good idea to determine when it's the best time to plant sunflowers by referring to the USDA zone info for Washington.

Planting Calendar for Sunflowers

Frost tolerance for sunflowers:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since sunflowers do not do well in cold weather it is important to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant sunflowers in Washington is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant sunflowers and expect a good harvest is probably August. Any later than that and your sunflowers may not have a chance to fully mature. You can get started a few weeks earlier by starting your sunflowers indoors.

Last Frost Date

On average the last frost is on April 15 in Washington. In the coldest months of winter you should expect an average low temperature of -5°F.

Since the USDA zone info for Washington is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Washington it frosts late in the year after April 15 so always be ready to protect your sunflowers in the event of one of those late frosts.

USDA Zone Info for Washington

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 Washington

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