One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of determining when it's a good idea to plant anchusa is to use the USDA zone info for Zone 5b.

Planting Calendar for Anchusa

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

Anchusa are very cold tolerant which means that you can plant them much earlier than other frost tender plants.

The earliest that you can plant anchusa in Zone 5b is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant anchusa and expect a good harvest is probably September. If you wait any later than that and your anchusa may not have a chance to grow to maturity. Starting your anchusa indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Zone 5b the average date of last frost happens on April 15. You can expect an average low temperature of -15°F in the coldest months of winter.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Zone 5b and it can change quite a bit from year to year. Since half of the time in Zone 5b you get surprised by a frost after April 15 be ready to protect your anchusa if you have one of those late frosts.

USDA Zone Info for Zone 5b

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 Zone 5b

You may be interested in your other planting guides for Zone 5b.