One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

By referring to the USDA zone info for Wyoming it's possible to figure out when you can plant sunflowers.

Planting Calendar for Sunflowers

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

You can not plant sunflowers until after all chance of frost has passed because they require warm weather.

The earliest that you can plant sunflowers in Wyoming 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. If you wait any later than that and your sunflowers may not have a chance to really do well. If you are starting your sunflowers indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Keep in mind that USDA zone info for Wyoming is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Wyoming it frosts late in the year after April 15 so just be sure to be ready to protect your sunflowers if you have one of those late frosts.

USDA Zone Info for Wyoming

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°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 -10°F.

Plants to Grow in Wyoming

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