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When to Plant Iceberg lettuce in Johnston, IA

One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant iceberg lettuce in Johnston can be estimated by referring to the USDA zone info.

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Planting Calendar for Iceberg lettuce

Frost tolerance for iceberg lettuce: Tolerant of a very small amount of frost.
When to plant: Up to 3 weeks before last frost.

Iceberg lettuce do well in mild cold which means that you can plant them a bit earlier in the year than more sensitive plants.

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

The earliest that you can plant iceberg lettuce in Johnston is March. However, you really should wait until April if you don't want to take any chances.

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

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Johnston. You can expect an average low temperature of -20°F in the coldest months of winter.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Johnston and it will vary from year to year. Half of the time in Johnston you get a frost after April 15 so be sure to be ready to cover your iceberg lettuce in the event of a late frost.

USDA Zone Info for Johnston

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 Johnston

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