One of the first steps you take when you are figuring out 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 best time to plant iceberg lettuce in Portland should be determined by looking at the USDA zone info.

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 are barely cold tolerant which means that you can plant them slightly earlier than more sensitive plants.

The earliest that you can plant iceberg lettuce in Portland 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. If you wait any later than that and your iceberg lettuce may not have a chance to fully mature. Starting your iceberg lettuce indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on March 15 in Portland. You should expect an average low temperature of 15°F in the coldest months of winter.

Remember that USDA zone info for Portland may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in Portland you get surprised by a frost after March 15 be ready to protect your iceberg lettuce in the event of a late frost.

USDA Zone Info for Portland

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Portland

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