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.

The USDA zone info for Waterloo can be looked at 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 are very cold tolerant you can plant them quite a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant lobelia in Waterloo 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. You probably don't want to wait any later than that or else your lobelia may not have a chance to fully mature. If you are starting your lobelia indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Waterloo the average date of last frost happens on April 15. You should expect an average low temperature of -10°F in the coldest months of winter.

Always keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Waterloo and it can change quite a bit from year to year. Half of the time in Waterloo it frosts late in the year after April 15 so make sure that you are prepared to cover your lobelia if you have a surprise late frost.

USDA Zone Info for Waterloo

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Waterloo

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