Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can figure out when it's possible to plant cilantro in Castle Rock by looking at the USDA zone info.

Planting Calendar for Cilantro

Frost tolerance for cilantro:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Cilantro do ok in moderate cold which tells us that you can plant them slightly earlier than other plants that might not handle the cold.

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

The last month that you can plant cilantro and expect a good harvest is probably August. You probably don't want to wait any later than that or else your cilantro may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your cilantro indoors.

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 is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Castle Rock it frosts late in the year after April 15 be ready to protect your cilantro 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.