When to Plant Leeks in Harlan, IA

The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By using the USDA zone info for Harlan you should be able to determine when it's the best time to plant leeks.


Planting Calendar for Leeks

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

Leeks do well in quite a bit of cold which tells us that you can plant them earlier in the year than plants that are more sensitive to the cold.

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

The earliest that you can plant leeks 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 leeks and expect a good harvest is probably September. Any later than that and your leeks may not have a chance to fully mature. If you are starting your leeks indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Harlan the average date of last frost happens on April 15. You can expect an average low temperature of -20°F in the coldest months of winter.

Since the USDA zone info for Harlan is an average the actual date of last frost changes from year to year. Half of the time in Harlan it frosts late in the year after April 15 so make sure that you are ready to cover your leeks in the event of a surprise late frost.

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.