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

The USDA zone info for Zone 5a can be looked at to determine when it's possible to plant aubretia.

Planting Calendar for Aubretia

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

Since aubretia do well in cold you can plant them much earlier in the year than other frost tender plants.

The earliest that you can plant aubretia in Zone 5a 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 aubretia and expect a good harvest is probably September. You probably don't want to wait any later than that or else your aubretia may not have a chance to grow to maturity. You can get started a little bit earlier by starting your aubretia indoors.

Last Frost Date

In Zone 5a the average date of last frost happens on April 15. You can expect an average low temperature of -20°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Zone 5a and it can change quite a bit from year to year. Since half of the time in Zone 5a you get surprised by a frost after April 15 be ready to cover your aubretia in the event of a late frost.

USDA Zone Info for Zone 5a

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Zone 5a

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