One of the best tools that you have as gardeners to help us determine 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 Merrill should be read to figure out when to plant lobelia.

Planting Calendar for Lobelia

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

Since lobelia do well in cold you can plant them quite a bit earlier in the year than more sensitive plants.

The earliest that you can plant lobelia in Merrill 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 lobelia and expect a good harvest is probably August. If you wait any later than that and your lobelia may not have a chance to really do well. If you are starting your lobelia indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on May 15 in Merrill. You should expect an average low temperature of -30°F in the coldest months of winter.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Merrill and it changes from year to year. Half of the time in Merrill you get a frost after May 15 so just be sure to be ready to protect your lobelia if you have a surprise late frost.

USDA Zone Info for Merrill

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Merrill

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