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 first opportunity to plant perilla in Castle Rock should be determined by using the USDA zone info.

Planting Calendar for Perilla

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

You really shouldn't plant perilla until after all chance of frost has passed because they are not cold tolerant.

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

Last Frost Date

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

Since the USDA zone info for Castle Rock is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Castle Rock it frosts late in the year after April 15 so make sure that you are prepared to cover your perilla in the event of 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.