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

It's possible to figure out when it's the best time to plant ajuga by looking at the USDA zone info for Naperville.

Planting Calendar for Ajuga

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

Since ajuga are very cold tolerant you can plant them much earlier in the year than other frost tender plants.

The earliest that you can plant ajuga in Naperville 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 ajuga and expect a good harvest is probably September. You probably don't want to wait any later than that or else your ajuga may not have a chance to fully mature. If you are starting your ajuga indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Naperville. You should 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 Naperville and it changes from year to year. Since half of the time in Naperville you get a frost after April 15 be ready to protect your ajuga in the event of one of those late frosts.

USDA Zone Info for Naperville

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 Naperville

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