frostdate name logo in white
frostdate name logo in white

When to Plant Spearmint in Johnstown, CO

One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The earliest that you can plant spearmint in Johnstown should be determined by reviewing the USDA zone info.


Planting Calendar for Spearmint

Frost tolerance for spearmint: Very tolerant of frost.
When to plant: Up to 7 weeks before last frost.

Spearmint are one of those plants that can tolerate quite a bit of cold weather which means that you can start planting them much earlier than more sensitive plants.

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

The earliest that you can plant spearmint in Johnstown 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 spearmint and expect a good harvest is probably September. You probably don't want to wait any later than that or else your spearmint may not have a chance to grow to maturity. If you are starting your spearmint indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Johnstown. You should expect an average low temperature of -15°F in the coldest months of winter.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Johnstown and it is different every year. Half of the time in Johnstown you get surprised by a frost after April 15 so be sure to be ready to protect your spearmint in the event of a late frost.

USDA Zone Info for Johnstown

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 Johnstown

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