Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can estimate when you can plant coral bells in Castle Rock by reviewing the USDA zone info.

Planting Calendar for Coral Bells

Frost tolerance for coral bells:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant coral bells a little earlier in the year because they do well in moderate cold.

The earliest that you can plant coral bells 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 coral bells and expect a good harvest is probably September. Any later than that and your coral bells may not have a chance to fully mature. If you are starting your coral bells indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Castle Rock. In the coldest months of winter you can expect an average low temperature of -15°F.

It's important to remember that USDA zone info for Castle Rock is an average and 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 ready to protect your coral bells if you have a late frost.

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.