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.

The first chance to plant verbena in Denver can be figured out by referring to 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 a bit earlier in the year because they do ok in moderate cold.

The earliest that you can plant verbena in Denver 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 grow to maturity. Starting your verbena 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 Denver. You can expect an average low temperature of -15°F in the coldest months of winter.

Remember that USDA zone info for Denver is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Denver it frosts late in the year after April 15 so make sure that you are ready to cover your verbena in the event of one of those late frosts.

USDA Zone Info for Denver

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 Denver

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