The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Castle Rock you can figure out when you can plant monkey flower by using the USDA zone info.

Planting Calendar for Monkey Flower

Frost tolerance for monkey flower:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

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

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

Last Frost Date

On average the last frost is on April 15 in Castle Rock. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Castle Rock is not always accurate the actual date of last frost changes from year to year. Half of the time in Castle Rock you get a frost after April 15 so be sure to be ready to cover your monkey flower 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.