When to Plant Lobelia in Manhattan, IL

One of the first steps you take when you are figuring out your gardening schedule is find your 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.

In Manhattan you can determine when you can plant lobelia by referring to the USDA zone info.


Planting Calendar for Lobelia

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

Lobelia are very cold tolerant which means that you can plant them a quite a bit earlier than plants that are more sensitive to the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant lobelia
Possibly ok, but a risky time to plant lobelia
Probably not a good time to plant lobelia

The earliest that you can plant lobelia in Manhattan 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 lobelia and expect a good harvest is probably September. If you wait any later than that and your lobelia may not have a chance to grow to maturity. You can get started a little bit earlier by starting your lobelia indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Manhattan. 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 Manhattan may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Manhattan last frost occurs after April 15 so be sure to be ready to cover your lobelia if you have a surprise late frost.

USDA Zone Info for Manhattan

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 Manhattan

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