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.

A way of estimating when to plant tarragon is to look at the USDA zone info for Denver.

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.

Tarragon do ok in moderate cold which tells us that you can get them planted just a bit earlier than more sensitive plants.

The earliest that you can plant tarragon in Denver 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. Any later than that and your tarragon may not have a chance to grow to maturity. 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 Denver. In the coldest months of winter you should expect an average low temperature of -15°F.

Remember that USDA zone info for Denver is not always accurate and the actual date of last frost changes from year to year. Half of the time in Denver there is a last frost after April 15 so make sure that you are prepared to cover your tarragon in the event of a surprise late frost.

USDA Zone Info for Denver

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 Denver

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