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

You should be able to estimate when it's possible to plant aubretia by using the USDA zone info for Portsmouth.

Planting Calendar for Aubretia

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

Aubretia tend to make it in pretty solid cold which means that you can plant them earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant aubretia in Portsmouth 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. Any later than that and your aubretia may not have a chance to fully mature. You can get started a little bit earlier by starting your aubretia indoors.

Last Frost Date

In Portsmouth the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -5°F.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Portsmouth and it is different every year. Since half of the time in Portsmouth you get surprised by a frost after April 15 be ready to cover your aubretia in the event of a surprise late frost.

USDA Zone Info for Portsmouth

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Portsmouth

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