When to Plant California Poppy in Castle Rock, CO

One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. 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 california poppy in Castle Rock should be determined by checking out the USDA zone info.


Planting Calendar for California Poppy

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

California Poppy do ok in very little cold which tells us that you can plant them slightly earlier in the year than plants that are more sensitive to the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant california poppy
Possibly ok, but a risky time to plant california poppy
Probably not a good time to plant california poppy

The earliest that you can plant california poppy 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 california poppy and expect a good harvest is probably August. Any later than that and your california poppy may not have a chance to grow to maturity. Starting your california poppy indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

Remember that USDA zone info for Castle Rock is an average and the actual date of last frost will vary from year to year. Half of the time in Castle Rock you get surprised by a frost after April 15 so just be sure to be ready to protect your california poppy 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.