Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By checking out the USDA zone info for Princeton you should be able to estimate when it's possible to plant romaine lettuce.

Planting Calendar for Romaine lettuce

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

You can plant romaine lettuce quite a bit earlier in the year because they are very cold tolerant.

The earliest that you can plant romaine lettuce in Princeton 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. You probably don't want to wait any later than that or else your romaine lettuce may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your romaine lettuce indoors.

Last Frost Date

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

Just be sure to remember that USDA zone info for Princeton may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Princeton you get a frost after April 15 so make sure that you are prepared to protect your romaine lettuce if you have a surprise late frost.

USDA Zone Info for Princeton

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°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 -10°F.

Plants to Grow in Princeton

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