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When to Plant Verbena in Castle Rock, CO

Before planting it is a good idea to find your USDA Zone info to figure out 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 USDA zone info for Castle Rock should be used to determine when it's the best time to plant verbena.


Planting Calendar for Verbena

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

Since verbena are one of those plants that can tolerate a tiny bit of cold weather you can plant them just a tiny bit earlier in the year than plants that are more sensitive to the cold.

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

The earliest that you can plant verbena 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 verbena and expect a good harvest is probably August. You probably don't want to wait any later than that or else your verbena may not have a chance to fully mature. Starting your verbena indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Castle Rock the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Castle Rock and it is different every year. Half of the time in Castle Rock you get surprised by a frost after April 15 so make sure that you are prepared to cover your verbena in the event of 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.