One of the best tools that you have as gardeners to help us figure out 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.

In Roselle you can figure out when it's a good idea to plant anchusa by looking at 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.

You can plant anchusa quite a bit 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 Roselle 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 fully mature. You can get started a few weeks earlier by starting your anchusa indoors.

Last Frost Date

In Roselle the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Roselle may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Roselle there is a last frost after April 15 be ready to cover your anchusa if you have one of those late frosts.

USDA Zone Info for Roselle

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 Roselle

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