One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By checking out the USDA zone info for Castle Rock you should be able to determine when you can plant fanflower.

Planting Calendar for Fanflower

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

Since fanflower do not do well in cold weather you must wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant fanflower 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 fanflower and expect a good harvest is probably August. Any later than that and your fanflower may not have a chance to fully mature. Starting your fanflower indoors is a great way to get them started a couple of weeks 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.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Castle Rock and it is different every year. Half of the time in Castle Rock there is a last frost after April 15 so make sure that you are ready to cover your fanflower 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.