The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Stillwater can be reviewed to estimate when you can plant anchusa.

Planting Calendar for Anchusa

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

You can plant anchusa much earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

The earliest that you can plant anchusa in Stillwater 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. 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 Stillwater. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Stillwater is just an average the actual date of last frost is different every year. Half of the time in Stillwater you get surprised by a frost after May 15 so make sure that you are ready to cover your anchusa in the event of one of those late frosts.

USDA Zone Info for Stillwater

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 Stillwater

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