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When to Plant Spearmint in Granite City, IL

One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant spearmint in Granite City can be figured out by using 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.

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

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 Granite City 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. If you wait any later than that and your spearmint may not have a chance to fully mature. If you are starting your spearmint indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Granite City. You should expect an average low temperature of -5°F in the coldest months of winter.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Granite City and it can change quite a bit from year to year. Half of the time in Granite City last frost occurs after April 15 so be sure to be ready to protect your spearmint in the event of a surprise late frost.

USDA Zone Info for Granite City

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-5°F
Highest Expected Low0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Granite City

You may be interested in your other planting guides for Granite City.