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 earliest that you can plant myosotis in Castle Rock can be figured out by referring to the USDA zone info.

Planting Calendar for Myosotis

Frost tolerance for myosotis:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since myosotis are moderately cold tolerant you can plant them a bit earlier in the year than more sensitive plants.

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

The last month that you can plant myosotis and expect a good harvest is probably September. Any later than that and your myosotis may not have a chance to really do well. If you are starting your myosotis indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for Castle Rock may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Castle Rock last frost occurs after April 15 so always be ready to cover your myosotis 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.