The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The earliest that you can plant streptocarpella in Castle Rock can be estimated by checking out the USDA zone info.

Planting Calendar for Streptocarpella

Frost tolerance for streptocarpella:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's probably not a good idea to plant streptocarpella until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant streptocarpella in Castle Rock is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant streptocarpella and expect a good harvest is probably August. You probably don't want to wait any later than that or else your streptocarpella may not have a chance to really do well. Starting your streptocarpella indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Always keep in mind that USDA zone info for Castle Rock is an average and the actual date of last frost will vary from year to year. Since half of the time in Castle Rock last frost occurs after April 15 be ready to cover your streptocarpella if you have 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.