One of the first steps you take when you are getting a good idea 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.

A way of determining when it's possible to plant romaine lettuce is to examine the USDA zone info for Pullman.

Planting Calendar for Romaine lettuce

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

Romaine lettuce are one of those plants that can tolerate quite a bit of cold weather which tells us that you can start planting them much earlier than other frost tender plants.

The earliest that you can plant romaine lettuce in Pullman 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 romaine lettuce and expect a good harvest is probably September. Any later than that and your romaine lettuce may not have a chance to grow to maturity. You can get started a little bit earlier by starting your romaine lettuce indoors.

Last Frost Date

In Pullman the average date of last frost happens on April 15. It might get as low as -5°F during the coldest months of winter.

Always keep in mind that USDA zone info for Pullman is not always accurate and the actual date of last frost will vary from year to year. Half of the time in Pullman there is a last frost after April 15 so make sure that you are ready to cover your romaine lettuce if you have a late frost.

USDA Zone Info for Pullman

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 Low	0°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 Pullman

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