When to Plant Romanesco in Castle Rock, CO

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.

It's a good idea to estimate when it's possible to plant romanesco by referring to the USDA zone info for Castle Rock.


Planting Calendar for Romanesco

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

You can plant romanesco just a bit earlier in the year because they do well in moderate cold.

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

The earliest that you can plant romanesco 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 romanesco and expect a good harvest is probably September. You probably don't want to wait any later than that or else your romanesco may not have a chance to grow to maturity. You can get started a little bit earlier by starting your romanesco indoors.

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.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Castle Rock and it changes from year to year. Since half of the time in Castle Rock it frosts late in the year after April 15 be ready to protect your romanesco 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.