One of the first steps you take when you are estimating 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.

The first opportunity to plant caladium in Helena should be estimated by looking at the USDA zone info.

Planting Calendar for Caladium

Frost tolerance for caladium:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

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

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

The last month that you can plant caladium and expect a good harvest is probably August. You probably don't want to wait any later than that or else your caladium may not have a chance to really do well. You can get started a little bit earlier by starting your caladium indoors.

Last Frost Date

In Helena the average date of last frost happens on May 15. You should expect an average low temperature of -25°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Helena and it changes from year to year. Half of the time in Helena there is a last frost after May 15 so just be sure to be ready to protect your caladium in the event of a late frost.

USDA Zone Info for Helena

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Helena

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