One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when it's the best time to plant aurinia in Zone 4a by using the USDA zone info.

Planting Calendar for Aurinia

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

You can plant aurinia a lot earlier in the year because they do well in cold.

The earliest that you can plant aurinia in Zone 4a 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 aurinia and expect a good harvest is probably August. If you wait any later than that and your aurinia may not have a chance to really do well. You can get started a few weeks earlier by starting your aurinia indoors.

Last Frost Date

In Zone 4a 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 Zone 4a is just an average the actual date of last frost will vary from year to year. Since half of the time in Zone 4a you get surprised by a frost after May 15 be ready to protect your aurinia in the event of a late frost.

USDA Zone Info for Zone 4a

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 Zone 4a

You may be interested in your other planting guides for Zone 4a.