One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By checking out the USDA zone info for Williston you will be able to figure out when it's possible to plant anchusa.

Planting Calendar for Anchusa

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

Anchusa can survive in cold weather which tells us that you can plant them earlier in the year than other frost tender plants.

The earliest that you can plant anchusa in Williston 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. If you wait any later than that and your anchusa may not have a chance to really do well. You can get started a couple of weeks earlier by starting your anchusa indoors.

Last Frost Date

In Williston the average date of last frost happens on May 15. You should expect an average low temperature of -30°F in the coldest months of winter.

Since the USDA zone info for Williston may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Williston there is a last frost after May 15 so make sure that you are ready to protect your anchusa in the event of one of those late frosts.

USDA Zone Info for Williston

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Williston

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