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

By reviewing the USDA zone info for Casper you should be able to estimate when it's the best time to plant tarragon.

Planting Calendar for Tarragon

Frost tolerance for tarragon:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since tarragon are barely cold tolerant you can plant them slightly earlier in the year than other plants that might not handle the cold.

The earliest that you can plant tarragon in Casper 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 tarragon and expect a good harvest is probably August. You probably don't want to wait any later than that or else your tarragon may not have a chance to really do well. You can get started a little bit earlier by starting your tarragon indoors.

Last Frost Date

The average date of last frost is April 15 in Casper. It might get as low as -20°F during the coldest months of winter.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Casper and it is different every year. Since half of the time in Casper it frosts late in the year after April 15 be ready to protect your tarragon in the event of one of those late frosts.

USDA Zone Info for Casper

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 Casper

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