One of the first steps you take when you are figuring out your gardening schedule is find your 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.

You can estimate when it's a good idea to plant anchusa in Oak Brook 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 very cold tolerant.

The earliest that you can plant anchusa in Oak Brook 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. 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 Oak Brook the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Oak Brook is not always accurate the actual date of last frost will vary from year to year. Half of the time in Oak Brook there is a last frost after April 15 so always be ready to cover your anchusa if you have a surprise late frost.

USDA Zone Info for Oak Brook

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 Oak Brook

You may be interested in your other planting guides for Oak Brook.