The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant aubretia in Castle Rock can be figured out by referring to the USDA zone info.

Planting Calendar for Aubretia

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

You can plant aubretia much earlier in the year because they do well in cold.

The earliest that you can plant aubretia in Castle Rock 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. If you wait any later than that and your aubretia may not have a chance to grow to maturity. If you are starting your aubretia indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Castle Rock the average date of last frost happens on April 15. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Castle Rock may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Castle Rock there is a last frost after April 15 so make sure that you are prepared to protect your aubretia in the event of one of those late frosts.

USDA Zone Info for Castle Rock

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 Castle Rock

You may be interested in your other planting guides for Castle Rock.