When to Plant Garden Mums in Westminster, CO

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

By looking at the USDA zone info for Westminster it's a good idea to figure out when to plant garden mums.


Planting Calendar for Garden Mums

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

Since garden mums are moderately cold tolerant you can plant them a bit earlier in the year than other frost tender plants.

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

The earliest that you can plant garden mums in Westminster 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 garden mums and expect a good harvest is probably September. Any later than that and your garden mums may not have a chance to fully mature. Starting your garden mums indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Westminster the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -15°F.

Just be sure to 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 Westminster and it can change quite a bit from year to year. Half of the time in Westminster it frosts late in the year after April 15 so just be sure to be ready to cover your garden mums in the event of a late frost.

USDA Zone Info for Westminster

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 Westminster

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