The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can estimate when to plant anchusa in Riverton by checking out the USDA zone info.

Planting Calendar for Anchusa

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

Since anchusa are very cold tolerant you can plant them a lot earlier in the year than more sensitive plants.

The earliest that you can plant anchusa in Riverton 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 anchusa and expect a good harvest is probably August. You probably don't want to wait any later than that or else your anchusa may not have a chance to really do well. Starting your anchusa indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Riverton. You should expect an average low temperature of -25°F in the coldest months of winter.

Since the USDA zone info for Riverton is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Riverton there is a last frost after May 15 so make sure that you are prepared to cover your anchusa if you have a surprise late frost.

USDA Zone Info for Riverton

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 Riverton

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