When to Plant Thyme in Harlan, IA

One of the first steps you take when you are determining 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.

A way of determining when to plant thyme is to check out the USDA zone info for Harlan.


Planting Calendar for Thyme

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

You can plant thyme quite a bit earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

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

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

Last Frost Date

On average all chance of frost has passed is on April 15 in Harlan. You can expect an average low temperature of -20°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 Harlan and it is different every year. Since half of the time in Harlan last frost occurs after April 15 be ready to cover your thyme if you have one of those late frosts.

USDA Zone Info for Harlan

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-20°F
Highest Expected Low-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Harlan

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