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When to Plant Forget-Me-Not in Castle Rock, CO

The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first chance to plant forget-me-not in Castle Rock should be estimated by looking at the USDA zone info.


Planting Calendar for Forget-Me-Not

Frost tolerance for forget-me-not: Tolerant of some frost.
When to plant: Up to 5 weeks before last frost.

Forget-Me-Not are one of those plants that can tolerate a little bit of cold weather which tells us that you can start planting them earlier than plants that are more sensitive to the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant forget-me-not
Possibly ok, but a risky time to plant forget-me-not
Probably not a good time to plant forget-me-not

The earliest that you can plant forget-me-not 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 forget-me-not and expect a good harvest is probably September. Any later than that and your forget-me-not may not have a chance to grow to maturity. If you are starting your forget-me-not 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. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Castle Rock is just an average 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 forget-me-not if you have a surprise 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.