The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Merrillville you can figure out when you can plant romaine lettuce by referring to the USDA zone info.

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 do well in quite a bit of cold which tells us that you can plant them a lot earlier in the year than other frost tender plants.

The earliest that you can plant romaine lettuce in Merrillville 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 really do well. You can get started a few weeks earlier by starting your romaine lettuce indoors.

Last Frost Date

In Merrillville the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -15°F.

It's important to remember that USDA zone info for Merrillville 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 Merrillville it frosts late in the year after April 15 be ready to cover your romaine lettuce if you have a surprise late frost.

USDA Zone Info for Merrillville

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 Merrillville

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