One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Merrillville can be used to estimate when it's the best time to plant dahlia.

Planting Calendar for Dahlia

Frost tolerance for dahlia:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's probably a bad idea to plant dahlia until after the last frost when the weather gets warmer because they require warm weather.

The earliest that you can plant dahlia in Merrillville is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant dahlia and expect a good harvest is probably August. If you wait any later than that and your dahlia may not have a chance to really do well. Starting your dahlia 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 April 15 in Merrillville. You should expect an average low temperature of -15°F in the coldest months of winter.

Keep in mind that USDA zone info for Merrillville is an average and the actual date of last frost will vary from year to year. Half of the time in Merrillville you get a frost after April 15 so make sure that you are prepared to cover your dahlia 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.