One of the first steps you take when you are estimating 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 determine when it's a good idea to plant tarragon by referring to the USDA zone info for Zone 4b.

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 do ok in moderate cold you can plant them slightly earlier in the year than more sensitive plants.

The earliest that you can plant tarragon in Zone 4b 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 tarragon and expect a good harvest is probably August. If you wait any later than that and your tarragon may not have a chance to really do well. You can get started a couple of weeks earlier by starting your tarragon indoors.

Last Frost Date

In Zone 4b the average date of last frost happens on May 15. In the coldest months of winter you can expect an average low temperature of -25°F.

It's important to remember that USDA zone info for Zone 4b may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in Zone 4b it frosts late in the year after May 15 be ready to protect your tarragon if you have a surprise late frost.

USDA Zone Info for Zone 4b

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Zone 4b

You may be interested in your other planting guides for Zone 4b.