When to Plant Celosia in Castle Rock, CO

Before planting it is a good idea to find your USDA Zone info to determine your garden 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 celosia in Castle Rock can be figured out by using the USDA zone info.


Planting Calendar for Celosia

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

Celosia do not do well in cold weather which tells us that it is necessary to wait until it warms up after all chance of frost has passed before you can plant them.

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

The earliest that you can plant celosia 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 celosia and expect a good harvest is probably August. If you wait any later than that and your celosia may not have a chance to really do well. You can get started a couple of weeks earlier by starting your celosia indoors.

Last Frost Date

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

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Castle Rock and it can change quite a bit from year to year. Since half of the time in Castle Rock last frost occurs after April 15 be ready to cover your celosia in the event of 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.