When to Plant Verbena in Longmont, CO

The USDA Zone info is a great tool for gardeners to help us figure out 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.

You can estimate when you can plant verbena in Longmont by looking at the USDA zone info.


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.

You can plant verbena slightly earlier in the year because they are barely cold tolerant.

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 Longmont 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. If you wait any later than that and your verbena may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your verbena indoors.

Last Frost Date

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

Since the USDA zone info for Longmont is not always accurate the actual date of last frost changes from year to year. Since half of the time in Longmont it frosts late in the year after April 15 be ready to cover your verbena in the event of one of those late frosts.

USDA Zone Info for Longmont

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 Longmont

You may be interested in your other planting guides for Longmont.