One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to figure out when to plant thyme by looking at the USDA zone info for Yankton.

Planting Calendar for Thyme

Frost tolerance for thyme:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

You can plant thyme much earlier in the year because they are very cold tolerant.

The earliest that you can plant thyme in Yankton is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant thyme and expect a good harvest is probably September. If you wait any later than that and your thyme may not have a chance to really do well. Starting your thyme indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Yankton. You should expect an average low temperature of -20°F in the coldest months of winter.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Yankton and it changes from year to year. Half of the time in Yankton you get a frost after April 15 so just be sure to be ready to cover your thyme in the event of a surprise late frost.

USDA Zone Info for Yankton

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

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

Plants to Grow in Yankton

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